diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
new file mode 100644
index 00000000..2bc35cb5
--- /dev/null
+++ b/.github/copilot-instructions.md
@@ -0,0 +1,94 @@
+# Copilot Instructions for PowerApps-Tooling
+
+## Build and Test
+
+This is a .NET SDK project (SDK 10.0, pinned in `global.json`). The solution is `src/PASopa.sln`.
+
+```shell
+# Build
+dotnet build src/PASopa.sln
+
+# Run all tests (Windows only — includes net48 targets)
+dotnet test --no-build --solution src/PASopa.sln
+
+# Run a specific test project
+dotnet test --no-build --project src/Persistence.Tests/Persistence.Tests.csproj
+dotnet test --no-build --project src/PAModelTests/PAModelTests.csproj
+
+# Run a single test by name
+dotnet test --no-build --project src/Persistence.Tests/Persistence.Tests.csproj --filter "FullyQualifiedName~MsappArchiveTests.SomeTestName"
+
+# Run tests for a specific target framework
+dotnet test --no-build --project src/Persistence.Tests/Persistence.Tests.csproj --framework net10.0
+
+# Clean repo (removes all build artifacts except src/.vs)
+scorch.cmd
+```
+
+Multi-targeting: Projects target `net8.0`, `net10.0`, and `net48`. Building `net48` requires Windows with .NET Framework 4.8 Developer Pack. On Linux/macOS, `net48` targets are skipped automatically.
+
+Warnings are treated as errors at the command line (`TreatWarningsAsErrors` is set in `Directory.Build.props`), but suppressed in VS IDE to avoid blocking development flow.
+
+## Architecture
+
+### Two library generations
+
+- **Persistence** (`src/Persistence/`): The active library (`Microsoft.PowerPlatform.PowerApps.Persistence`). Handles the modern `.msapp` format with YAML-based source representation (`.pa.yaml` files). This is where new work happens. The 'Source Code' schema of canvas YAML (aka PaYamlV3).
+- **PAModel** (`src/PAModel/`): Legacy library (`Microsoft.PowerPlatform.Formulas.Tools`) for the older PASopa pack/unpack tool. No longer actively developed, although some maintenance may still occur. The 'Experimental' schema of canvas YAML (aka PaYamlV1).
+
+### Persistence library structure
+
+- **`Compression/`** — Cross-platform archive abstraction (`PaArchive`, `PaArchiveEntry`, `PaArchivePath`) with both sync and async extract APIs.
+- **`MsApp/`** — Archive model: `MsappArchive` wraps `ZipArchive` to read/write `.msapp` files. `MsappLayoutConstants` centralizes all archive entry paths. Factory pattern via `IMsappArchiveFactory`.
+- **`MsappPacking/`** — Core pack/unpack orchestration: `MsappPackingService` converts between `.msapp` archives and unpacked source directory structures. Unpack validates version constraints (`MinSupportedMSAppStructureVersion`, `MinSupportedDocVersion`) before extracting. Pack reads `.msapr` reference files and `Src/**/*.pa.yaml` to rebuild archives.
+- **`PaYaml/`** — YAML serialization layer: `PaYamlSerializer` is the central entry point, built on YamlDotNet. Uses strongly-typed models like `NamedObject<T>` for YAML document structure. The models in `src\Persistence\PaYaml\Models\SchemaV3\**` represent the 'Source Code' schema of canvas YAML (PaYamlV3). These models should match the schema defined in `src/schemas/pa-yaml/v3.0/` and are used for both serialization and deserialization.
+- **`TfmAdapters/` and `TfmExtensions/`** — Polyfills and adapter shims so modern C# features work on `net48` (using PolySharp).
+- **`Extensions/`** — Helper extension methods for JSON, LINQ, and strings.
+
+### Dependency injection
+
+Services are registered via `IServiceCollection` extension methods using `TryAddSingleton`:
+- `services.AddMsappArchiveFactory()` — registers `IMsappArchiveFactory`
+- `services.AddMsappPackingService()` — registers `MsappPackingService` and its dependencies
+
+### Error handling
+
+`PersistenceLibraryException` with categorized `PersistenceErrorCode` (1xxx = System, 2xxx = Serialization, 3xxx = Deserialization, 4xxx = Archive). Exceptions carry optional context: `MsappEntryFullPath`, `LineNumber`, `Column`, `JsonPath`.
+
+### Schemas
+
+JSON schemas for the `.pa.yaml` format live in `src/schemas/pa-yaml/` (versioned: `v3.0`). Published schemas go to the root `schemas/` directory via `src/schemas/publish.ps1`.
+
+## `YamlValidator` project
+
+This project only worked with PaYamlV2, which has been deprecated. It's only here for historical reference and as a starter in case we want to repurpose it to validate PaYamlV3.
+
+## Conventions
+
+### Testing
+
+- Test framework is **MSTest** via MSTest.Sdk (configured in `global.json`).
+- Test classes inherit from `TestBase` (which extends `VSTestBase`) for shared helpers like `JsonShouldBeEquivalentTo()`, `ToJsonElement()`, and test output folder management.
+- Serialization tests inherit from `SerializationTestBase`.
+- Assertions use **FluentAssertions** (pinned ≤7.x due to license — see `Directory.Packages.props`).
+- Test data lives in `_TestData/` directories within test projects, organized by scenario (`ValidYaml/`, `InvalidYaml/`, `AppsWithYaml/`, etc.).
+- `Persistence.Testing` project provides shared test utilities (`CapturingLogger<T>`, `FilePathComparer`).
+
+### Package version constraints
+
+Several packages have upper version limits due to license changes — these are documented with `WARNING` comments in `src/Directory.Packages.props`:
+- FluentAssertions: ≤7.x
+- JsonSchema.Net: ≤8.0.5
+- Yaml2JsonNode: ≤2.4.0
+
+### Code style
+
+- C# language version: 13.0 (set in Persistence csproj)
+- Nullable reference types: enabled
+- File-scoped namespaces (e.g., `namespace Foo;`)
+- Primary constructors used for DI (e.g., `MsappPackingService(IMsappArchiveFactory, ...)`)
+- Root namespace: `Microsoft.PowerPlatform.PowerApps.Persistence` for Persistence, `Microsoft.PowerPlatform.Formulas.Tools` for PAModel
+- Copyright header: `// Copyright (c) Microsoft Corporation.` + `// Licensed under the MIT License.`
+- Central package management via `src/Directory.Packages.props`
+- Global usings for `System`, `System.Collections.Generic`, `System.Diagnostics` defined in `src/Directory.Build.props`
+- InternalsVisibleTo for test assemblies is configured with signing key in `Directory.Build.targets`
diff --git a/src/PAModel/.editorconfig b/src/PAModel/.editorconfig
index c4297cbe..8939a81c 100644
--- a/src/PAModel/.editorconfig
+++ b/src/PAModel/.editorconfig
@@ -1,13 +1,6 @@
 [*.cs]
 
-# Category overries:
-# Disabling these categories because the original implementation didn't have them on and we're not making changes to it at this time.
-dotnet_analyzer_diagnostic.category-Design.severity           = silent
-dotnet_analyzer_diagnostic.category-Globalization.severity    = silent
-dotnet_analyzer_diagnostic.category-Performance.severity      = silent
-dotnet_analyzer_diagnostic.category-Usage.severity            = silent
-
 # Rule overrides:
 
-# CA1716: Identifiers should not match keywords
-dotnet_diagnostic.CA1716.severity = silent
+# IDE0130: Namespace does not match folder structure
+dotnet_diagnostic.IDE0130.severity = silent
diff --git a/src/PAModel/CanvasDocument.cs b/src/PAModel/CanvasDocument.cs
index e22a799b..ee1372f4 100644
--- a/src/PAModel/CanvasDocument.cs
+++ b/src/PAModel/CanvasDocument.cs
@@ -33,7 +33,7 @@ public class CanvasDocument
 
     // Track all unknown "files". Ensures round-tripping isn't lossy.
     // Only contains files of FileKind.Unknown
-    internal Dictionary<FilePath, FileEntry> _unknownFiles = new();
+    internal Dictionary<FilePath, FileEntry> _unknownFiles = [];
 
     // Key is Top Parent Control Name for both _screens and _components
     internal Dictionary<string, BlockNode> _screens = new(StringComparer.Ordinal);
@@ -47,7 +47,7 @@ public class CanvasDocument
     // Also includes entries for DataSources made from a DataComponent
     // Key is parent entity name (datasource name for non cds data sources)
     internal Dictionary<string, List<DataSourceEntry>> _dataSources = new(StringComparer.Ordinal);
-    internal List<string> _screenOrder = new();
+    internal List<string> _screenOrder = [];
 
     internal HeaderJson _header;
     internal DocumentPropertiesJson _properties;
@@ -88,7 +88,7 @@ public class CanvasDocument
     internal ChecksumJson _checksum;
 
     // Track all asset files, key is file name
-    internal Dictionary<FilePath, FileEntry> _assetFiles = new();
+    internal Dictionary<FilePath, FileEntry> _assetFiles = [];
 
     internal UniqueIdRestorer _idRestorer;
 
@@ -96,7 +96,7 @@ public class CanvasDocument
     // This dictionary stores the metadata information for that file - like OriginalName, NewFileName, Path...
     // Key is a (case-insensitive) new fileName of the resource.
     // Reason for using FileName of the resource as the key is to avoid name collision across different types eg. Images/close.png, Videos/close.mp4.
-    internal Dictionary<string, LocalAssetInfoJson> _localAssetInfoJson = new();
+    internal Dictionary<string, LocalAssetInfoJson> _localAssetInfoJson = [];
     internal static string AssetFilePathPrefix = @"Assets\";
 
     #region Save/Load
@@ -123,11 +123,9 @@ public static (CanvasDocument, ErrorContainer) LoadFromMsapp(string fullPathToMs
             return (null, errors);
         }
 
-        using (var stream = new FileStream(fullPathToMsApp, FileMode.Open, FileAccess.Read, FileShare.Read))
-        {
-            var doc = Wrapper(() => MsAppSerializer.Load(stream, errors), errors);
-            return (doc, errors);
-        }
+        using var stream = new FileStream(fullPathToMsApp, FileMode.Open, FileAccess.Read, FileShare.Read);
+        var doc = Wrapper(() => MsAppSerializer.Load(stream, errors), errors);
+        return (doc, errors);
     }
 
     public static (CanvasDocument, ErrorContainer) LoadFromMsapp(Stream streamToMsapp)
@@ -287,7 +285,7 @@ internal CanvasDocument(CanvasDocument other)
         _templateStore = new TemplateStore(other._templateStore);
 
         _dataSources = other._dataSources.JsonClone();
-        _screenOrder = new List<string>(other._screenOrder);
+        _screenOrder = [.. other._screenOrder];
 
         _header = other._header.JsonClone();
         _properties = other._properties.JsonClone();
@@ -323,7 +321,7 @@ internal void AddDataSourceForLoad(DataSourceEntry ds, int? order = null)
         var key = ds.RelatedEntityName ?? ds.Name;
         if (!_dataSources.TryGetValue(key, out var list))
         {
-            list = new List<DataSourceEntry>();
+            list = [];
             _dataSources.Add(key, list);
         }
 
@@ -486,14 +484,17 @@ internal void OnLoadComplete(ErrorContainer errors)
         }
 
         // Integrity checks.
-        foreach (var kv in _connections.NullOk())
+        if (_connections is not null)
         {
-            var connection = kv.Value;
-
-            if (kv.Key != connection.id)
+            foreach (var kv in _connections)
             {
-                errors.FormatNotSupported($"Document consistency error. Connection id mismatch");
-                throw new DocumentException();
+                var connection = kv.Value;
+
+                if (kv.Key != connection.id)
+                {
+                    errors.FormatNotSupported($"Document consistency error. Connection id mismatch");
+                    throw new DocumentException();
+                }
             }
         }
     }
@@ -514,7 +515,7 @@ internal HashSet<string> GetImportedComponents()
 
     private static FilePath GetAssetFilePathWithoutPrefix(string path)
     {
-        return FilePath.FromMsAppPath(path.Substring(AssetFilePathPrefix.Length));
+        return FilePath.FromMsAppPath(path[AssetFilePathPrefix.Length..]);
     }
 
     internal void StabilizeAssetFilePaths(ErrorContainer errors)
@@ -676,16 +677,11 @@ private void RestoreAssetFilePaths(ErrorContainer errors)
     }
 
     // Helper for traversing and ensuring unique control names.
-    internal class UniqueControlNameVisitor
+    internal class UniqueControlNameVisitor(ErrorContainer errors)
     {
+        private readonly ErrorContainer _errors = errors;
         // Control names are case sensitive.
         private readonly Dictionary<string, SourceLocation?> _names = new(StringComparer.Ordinal);
-        private readonly ErrorContainer _errors;
-
-        public UniqueControlNameVisitor(ErrorContainer errors)
-        {
-            _errors = errors;
-        }
 
         public void Visit(BlockNode node)
         {
diff --git a/src/PAModel/Checksum/ChecksumMaker.cs b/src/PAModel/Checksum/ChecksumMaker.cs
index c702fe9e..a85560e2 100644
--- a/src/PAModel/Checksum/ChecksumMaker.cs
+++ b/src/PAModel/Checksum/ChecksumMaker.cs
@@ -25,7 +25,7 @@ public class ChecksumMaker
     public const string ChecksumName = "checksum.json";
 
     // Track a checksum per file and then merge into a single one at the end.
-    private readonly Dictionary<string, byte[]> _files = new();
+    private readonly Dictionary<string, byte[]> _files = [];
 
     public static (string wholeChecksum, Dictionary<string, string> perFileChecksum) GetChecksum(string fullpathToMsApp)
     {
@@ -80,8 +80,8 @@ internal static byte[] ChecksumFile<T>(string filename, byte[] bytes)
     }
 
     // These paths are json double-encoded and need a different comparer.
-    private static readonly HashSet<string> _jsonDouble = new()
-    {
+    private static readonly HashSet<string> _jsonDouble =
+    [
         "LocalConnectionReferences",
         "LocalDatabaseReferences",
         "LibraryDependencies",
@@ -95,21 +95,21 @@ internal static byte[] ChecksumFile<T>(string filename, byte[] bytes)
         "Template\\DynamicControlDefinitionJson\\Properties",
         "Template\\DynamicControlDefinitionJson\\Resources",
         "Template\\DynamicControlDefinitionJson\\SubscribedFunctionalities",
-    };
+    ];
 
     // These paths are xml double-encoded and need a different comparer.
-    private static readonly HashSet<string> _xmlDouble = new()
-    {
+    private static readonly HashSet<string> _xmlDouble =
+    [
         "UsedTemplates\\Template",
         "DataSources\\WadlMetadata\\WadlXml",
-    };
+    ];
 
     // Helper for identifying which paths are double encoded.
     // All of these should be resolved and fixed by the server.
     private class Context
     {
         public string Filename;
-        public Stack<string> s = new();
+        public Stack<string> s = [];
 
         public void Push(string path)
         {
@@ -187,7 +187,7 @@ internal static string ChecksumToString(byte[] bytes)
     internal static int GetChecksumVersion(string checksum)
     {
         var version = checksum.Split('_').First();
-        return int.Parse(version.Substring(1));
+        return int.Parse(version[1..]);
     }
 
     /// <summary>
diff --git a/src/PAModel/Checksum/IHashMaker.cs b/src/PAModel/Checksum/IHashMaker.cs
index 6d4c4d78..aeead931 100644
--- a/src/PAModel/Checksum/IHashMaker.cs
+++ b/src/PAModel/Checksum/IHashMaker.cs
@@ -37,11 +37,11 @@ internal class Sha256HashMaker : IHashMaker, IDisposable
     private static readonly byte[] _endObj = "}"u8.ToArray();
     private static readonly byte[] _startArray = "["u8.ToArray();
     private static readonly byte[] _endArray = "]"u8.ToArray();
-    private static readonly byte[] _null = new byte[] { 254 };
-    private static readonly byte[] _true = new byte[] { 1 };
-    private static readonly byte[] _false = new byte[] { 0 };
+    private static readonly byte[] _null = [254];
+    private static readonly byte[] _true = [1];
+    private static readonly byte[] _false = [0];
 
-    private static readonly byte[] _marker = new byte[] { 255 };
+    private static readonly byte[] _marker = [255];
 
     public Sha256HashMaker()
     {
diff --git a/src/PAModel/ControlTemplates/CommonControlProperties.cs b/src/PAModel/ControlTemplates/CommonControlProperties.cs
index 71302e03..f8da2784 100644
--- a/src/PAModel/ControlTemplates/CommonControlProperties.cs
+++ b/src/PAModel/ControlTemplates/CommonControlProperties.cs
@@ -10,7 +10,7 @@ namespace Microsoft.PowerPlatform.Formulas.Tools.ControlTemplates;
 internal class CommonControlProperties
 {
     // Key is property name
-    private readonly Dictionary<string, ControlProperty> _properties = new();
+    private readonly Dictionary<string, ControlProperty> _properties = [];
 
     private const string FileName = "Microsoft.PowerPlatform.Formulas.Tools.ControlTemplates.commonStyleProperties.xml";
     private static CommonControlProperties _instance;
diff --git a/src/PAModel/ControlTemplates/ControlTemplate.cs b/src/PAModel/ControlTemplates/ControlTemplate.cs
index 6802b05b..8b4f3687 100644
--- a/src/PAModel/ControlTemplates/ControlTemplate.cs
+++ b/src/PAModel/ControlTemplates/ControlTemplate.cs
@@ -20,7 +20,7 @@ public ControlTemplate(string name, string version, string id)
         Name = name;
         Version = version;
         Id = id;
-        InputDefaults = new Dictionary<string, string>();
-        VariantDefaultValues = new Dictionary<string, Dictionary<string, string>>();
+        InputDefaults = [];
+        VariantDefaultValues = [];
     }
 }
diff --git a/src/PAModel/ControlTemplates/DynamicProperties.cs b/src/PAModel/ControlTemplates/DynamicProperties.cs
index 86a546ed..7567bee2 100644
--- a/src/PAModel/ControlTemplates/DynamicProperties.cs
+++ b/src/PAModel/ControlTemplates/DynamicProperties.cs
@@ -21,8 +21,8 @@ internal static bool AddsChildDynamicProperties(string template, string variant)
     }
 
 
-    private static readonly HashSet<string> _supportsNestedControls = new()
-    {
+    private static readonly HashSet<string> _supportsNestedControls =
+    [
         "dataCard",
         "dataGrid",
         "dataTable",
@@ -38,7 +38,7 @@ internal static bool AddsChildDynamicProperties(string template, string variant)
         "layoutContainer",
         "pcfDataField",
         "typedDataCard",
-    };
+    ];
 
     private static readonly IReadOnlyDictionary<string, Func<string, DefaultRuleHelper, string>>
         PropertyDefaultScriptGetters = new Dictionary<string, Func<string, DefaultRuleHelper, string>>() {
diff --git a/src/PAModel/EditorState/TemplateStore.cs b/src/PAModel/EditorState/TemplateStore.cs
index 57af4b89..c7ed8cb4 100644
--- a/src/PAModel/EditorState/TemplateStore.cs
+++ b/src/PAModel/EditorState/TemplateStore.cs
@@ -12,7 +12,7 @@ internal class TemplateStore
 
     public TemplateStore()
     {
-        Contents = new Dictionary<string, CombinedTemplateState>();
+        Contents = [];
     }
 
     public TemplateStore(TemplateStore other)
diff --git a/src/PAModel/Entropy.cs b/src/PAModel/Entropy.cs
index 1e33e6e6..b789e7ab 100644
--- a/src/PAModel/Entropy.cs
+++ b/src/PAModel/Entropy.cs
@@ -95,7 +95,7 @@ internal class PropertyEntropy
     public HashSet<string> AppTestsMissingStepsMetadata { get; set; } = new HashSet<string>(StringComparer.Ordinal);
 
     // Key is connection id, value is connection instance id
-    public Dictionary<string, string> LocalConnectionIDReferences { get; set; } = new Dictionary<string, string>();
+    public Dictionary<string, string> LocalConnectionIDReferences { get; set; } = [];
 
     // Key is test rule, value is test screen id without Screen name
     public Dictionary<string, string> RuleScreenIdWithoutScreen { get; set; } = new Dictionary<string, string>(StringComparer.Ordinal);
@@ -192,8 +192,8 @@ public static string GetResourcesJsonIndicesKey(ResourceJson resource)
     // Removing the 'ContentKind-' gives the resource name
     public static string GetResourceNameFromKey(string key)
     {
-        var prefix = key.Split(new char[] { '-' }).First();
-        return key.Substring(prefix.Length + 1);
+        var prefix = key.Split(['-']).First();
+        return key[(prefix.Length + 1)..];
     }
 
     public void SetHeaderLastSaved(DateTime? x)
@@ -274,7 +274,7 @@ public int GetGroupControlOrder(string groupName, string childName)
 
     public void AddDataTableControlJson(string controlName, string json)
     {
-        DataTableCustomControlTemplateJsons ??= new Dictionary<string, string>();
+        DataTableCustomControlTemplateJsons ??= [];
 
         DataTableCustomControlTemplateJsons.Add(controlName, json);
     }
diff --git a/src/PAModel/Extensions/CollectionsExtensions.cs b/src/PAModel/Extensions/CollectionsExtensions.cs
index 4b8d34d6..05883d71 100644
--- a/src/PAModel/Extensions/CollectionsExtensions.cs
+++ b/src/PAModel/Extensions/CollectionsExtensions.cs
@@ -8,18 +8,6 @@ namespace Microsoft.PowerPlatform.Formulas.Tools.Extensions;
 
 public static class CollectionsExtensions
 {
-    // Allows using with { } initializers, which require an Add() method.
-    public static void Add<T>(this Stack<T> stack, T item)
-    {
-        stack.Push(item);
-    }
-
-    public static IEnumerable<T> NullOk<T>(this IEnumerable<T> list)
-    {
-        if (list == null) return Enumerable.Empty<T>();
-        return list;
-    }
-
     public static void AddRange<TKey, TValue>(
         this IDictionary<TKey, TValue> thisDictionary,
         IEnumerable<KeyValuePair<TKey, TValue>> other)
@@ -55,9 +43,7 @@ public static TValue GetOrCreate<TKey, TValue>(this IDictionary<TKey, TValue> di
     public static IList<T> Clone<T>(this IList<T> obj)
         where T : ICloneable<T>
     {
-        if (obj == null)
-            return null;
-        return obj.Select(item => item.Clone()).ToList();
+        return obj?.Select(item => item.Clone()).ToList();
     }
 
 }
diff --git a/src/PAModel/Extensions/JsonExtensions.cs b/src/PAModel/Extensions/JsonExtensions.cs
index 86aef0ba..2632b233 100644
--- a/src/PAModel/Extensions/JsonExtensions.cs
+++ b/src/PAModel/Extensions/JsonExtensions.cs
@@ -29,35 +29,35 @@ private static JsonSerializerOptions GetJsonOptions()
         return opts;
     }
 
-    public static JsonSerializerOptions _jsonOpts = GetJsonOptions();
+    internal static JsonSerializerOptions JsonOpts = GetJsonOptions();
 
     // https://stackoverflow.com/questions/58138793/system-text-json-jsonelement-toobject-workaround
 
     public static string JsonSerialize<T>(T obj)
     {
-        return JsonSerializer.Serialize(obj, _jsonOpts);
+        return JsonSerializer.Serialize(obj, JsonOpts);
     }
 
     public static T JsonParse<T>(string json)
     {
-        return JsonSerializer.Deserialize<T>(json, _jsonOpts);
+        return JsonSerializer.Deserialize<T>(json, JsonOpts);
     }
 
 
     public static T ToObject<T>(this JsonElement element)
     {
         var json = element.GetRawText();
-        return JsonSerializer.Deserialize<T>(json, _jsonOpts);
+        return JsonSerializer.Deserialize<T>(json, JsonOpts);
     }
     public static T ToObject<T>(this JsonDocument document)
     {
         var json = document.RootElement.GetRawText();
-        return JsonSerializer.Deserialize<T>(json, _jsonOpts);
+        return JsonSerializer.Deserialize<T>(json, JsonOpts);
     }
 
     public static byte[] ToBytes(this JsonElement e)
     {
-        var bytes = JsonSerializer.SerializeToUtf8Bytes(e, _jsonOpts);
+        var bytes = JsonSerializer.SerializeToUtf8Bytes(e, JsonOpts);
         return bytes;
     }
 
@@ -65,8 +65,8 @@ public static byte[] ToBytes(this JsonElement e)
     // but don't want to mutate the original.
     public static T JsonClone<T>(this T obj)
     {
-        var str = JsonSerializer.Serialize(obj, _jsonOpts);
-        var obj2 = JsonSerializer.Deserialize<T>(str, _jsonOpts);
+        var str = JsonSerializer.Serialize(obj, JsonOpts);
+        var obj2 = JsonSerializer.Deserialize<T>(str, JsonOpts);
         return obj2;
     }
 
diff --git a/src/PAModel/Extensions/StringExtensions.cs b/src/PAModel/Extensions/StringExtensions.cs
index 27cb9554..7b31c981 100644
--- a/src/PAModel/Extensions/StringExtensions.cs
+++ b/src/PAModel/Extensions/StringExtensions.cs
@@ -9,7 +9,7 @@ public static class StringExtensions
 {
     public static string UnEscapePAString(this string text)
     {
-        return text.Substring(1, text.Length - 2).Replace("\"\"", "\"");
+        return text[1..^1].Replace("\"\"", "\"");
     }
 
     public static string EscapePAString(this string text)
@@ -19,11 +19,8 @@ public static string EscapePAString(this string text)
 
     public static string FirstCharToUpper(this string input)
     {
-        return input switch
-        {
-            null => throw new ArgumentNullException(nameof(input)),
-            "" => throw new ArgumentException($"{nameof(input)} cannot be empty", nameof(input)),
-            _ => input.First().ToString().ToUpper() + input.Substring(1)
-        };
+        ThrowIfNullOrEmpty(input);
+
+        return $"{char.ToUpper(input[0])}{input[1..]}";
     }
 }
diff --git a/src/PAModel/IO/ControlPath.cs b/src/PAModel/IO/ControlPath.cs
index 0975588a..ad71c096 100644
--- a/src/PAModel/IO/ControlPath.cs
+++ b/src/PAModel/IO/ControlPath.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+using System.Collections.Immutable;
 using System.Linq;
 
 namespace Microsoft.PowerPlatform.Formulas.Tools.IO;
@@ -10,17 +11,19 @@ namespace Microsoft.PowerPlatform.Formulas.Tools.IO;
 /// Each segment is a control name
 /// </summary>
 [DebuggerDisplay("{string.Join('.', _segments)}")]
-internal class ControlPath
+internal class ControlPath(IEnumerable<string> segments)
 {
+    public static ControlPath Empty => new([]);
+
     // switch this to be a queue?
-    private readonly List<string> _segments;
-    public string Current => _segments.Any() ? _segments[0] : null;
-    public static ControlPath Empty => new(new List<string>());
+    private readonly ImmutableArray<string> _segments = [.. segments];
+
+    public string Current => _segments.Length != 0 ? _segments[0] : null;
 
     public ControlPath Next()
     {
         var newSegments = new List<string>();
-        for (var i = 1; i < _segments.Count; ++i)
+        for (var i = 1; i < _segments.Length; ++i)
         {
             newSegments.Add(_segments[i]);
         }
@@ -36,11 +39,6 @@ public ControlPath Append(string controlName)
         return new ControlPath(newPath);
     }
 
-    public ControlPath(List<string> segments)
-    {
-        _segments = segments;
-    }
-
     public static bool operator ==(ControlPath left, ControlPath right)
     {
         return left?.Equals(right) ?? right is null;
@@ -54,7 +52,7 @@ public ControlPath(List<string> segments)
     public override bool Equals(object obj)
     {
         return obj is ControlPath other &&
-            other._segments.Count == _segments.Count &&
+            other._segments.Length == _segments.Length &&
             _segments.SequenceEqual(other._segments);
     }
 
diff --git a/src/PAModel/IO/DirectoryReader.cs b/src/PAModel/IO/DirectoryReader.cs
index b73947d7..ae2b2e72 100644
--- a/src/PAModel/IO/DirectoryReader.cs
+++ b/src/PAModel/IO/DirectoryReader.cs
@@ -64,7 +64,7 @@ public T ToObject<T>()
             else
             {
                 var str = File.ReadAllText(_fullpath);
-                return JsonSerializer.Deserialize<T>(str, JsonExtensions._jsonOpts);
+                return JsonSerializer.Deserialize<T>(str, JsonExtensions.JsonOpts);
             }
         }
 
@@ -81,7 +81,7 @@ public Entry[] EnumerateFiles(string subdir, string pattern = "*", bool searchSu
 
         if (!Directory.Exists(root))
         {
-            return new Entry[0];
+            return [];
         }
 
         var fullPaths = Directory.EnumerateFiles(root, pattern, searchSubdirectories ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly);
@@ -104,7 +104,7 @@ public DirectoryReader[] EnumerateDirectories(string subdir, string pattern = "*
 
         if (!Directory.Exists(root))
         {
-            return new DirectoryReader[0];
+            return [];
         }
 
         var fullPaths = Directory.EnumerateDirectories(root, pattern, searchSubdirectories ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly);
diff --git a/src/PAModel/IO/DirectoryWriter.cs b/src/PAModel/IO/DirectoryWriter.cs
index 2fe0388e..6f2b2640 100644
--- a/src/PAModel/IO/DirectoryWriter.cs
+++ b/src/PAModel/IO/DirectoryWriter.cs
@@ -68,7 +68,7 @@ public void WriteAllJson<T>(string subdir, FilePath filename, T obj)
         }
         else
         {
-            var text = JsonSerializer.Serialize(obj, JsonExtensions._jsonOpts);
+            var text = JsonSerializer.Serialize(obj, JsonExtensions.JsonOpts);
             text = JsonNormalizer.Normalize(text);
             WriteAllText(subdir, filename, text);
         }
@@ -77,7 +77,7 @@ public void WriteAllJson<T>(string subdir, FilePath filename, T obj)
     // Use this if the filename is already escaped.
     public void WriteAllJson<T>(string subdir, string filename, T obj)
     {
-        var text = JsonSerializer.Serialize(obj, JsonExtensions._jsonOpts);
+        var text = JsonSerializer.Serialize(obj, JsonExtensions.JsonOpts);
         text = JsonNormalizer.Normalize(text);
         WriteAllText(subdir, filename, text);
     }
diff --git a/src/PAModel/IO/FilePath.cs b/src/PAModel/IO/FilePath.cs
index 5554286a..1afe9784 100644
--- a/src/PAModel/IO/FilePath.cs
+++ b/src/PAModel/IO/FilePath.cs
@@ -15,11 +15,17 @@ public class FilePath
     public const int MaxNameLength = 50;
     private const string yamlExtension = ".fx.yaml";
     private const string editorStateExtension = ".editorstate.json";
+
     private readonly string[] _pathSegments;
 
     public FilePath(params string[] segments)
     {
-        _pathSegments = segments ?? (new string[] { });
+        _pathSegments = segments ?? [];
+    }
+
+    public FilePath(IEnumerable<string> segments)
+    {
+        _pathSegments = segments?.ToArray() ?? [];
     }
 
     public static bool IsYamlFile(FilePath path)
@@ -52,7 +58,7 @@ public string ToMsAppPath()
         var path = string.Join("\\", _pathSegments);
 
         // Some paths mistakenly start with DirectorySepChar in the msapp,
-        // We replaced it with `_/` when writing, remove that now. 
+        // We replaced it with `_/` when writing, remove that now.
         if (path.StartsWith(FileEntry.FilenameLeadingUnderscore.ToString()))
         {
             path = path.TrimStart(FileEntry.FilenameLeadingUnderscore);
@@ -75,19 +81,14 @@ public static void EnsurePathRooted(string path)
     /// </summary>
     public static string GetResourceRelativePath(ContentKind contentType)
     {
-        switch (contentType)
+        return contentType switch
         {
-            case ContentKind.Image:
-                return @"Assets\Images";
-            case ContentKind.Audio:
-                return @"Assets\Audio";
-            case ContentKind.Video:
-                return @"Assets\Video";
-            case ContentKind.Pdf:
-                return @"Assets\Pdf";
-            default:
-                throw new NotSupportedException("Unrecognized Content Kind for local resource");
-        }
+            ContentKind.Image => @"Assets\Images",
+            ContentKind.Audio => @"Assets\Audio",
+            ContentKind.Video => @"Assets\Video",
+            ContentKind.Pdf => @"Assets\Pdf",
+            _ => throw new NotSupportedException("Unrecognized Content Kind for local resource"),
+        };
     }
 
     /// <summary>
@@ -103,7 +104,7 @@ public static string GetResourceRelativePath(ContentKind contentType)
     /// <exception cref="ArgumentNullException">Thrown if <paramref name="relativeTo"/> or path is <c>null</c> or an empty string.</exception>
     /// <remarks>
     /// Want to use Path.GetRelativePath() from Net 2.1. But since we target netstandard 2.0, we need to shim it.
-    /// Convert to URIs and make the relative path. 
+    /// Convert to URIs and make the relative path.
     /// see https://stackoverflow.com/questions/275689/how-to-get-relative-path-from-absolute-path
     /// For reference, see Core's impl at: https://github.com/dotnet/runtime/blob/main/src/libraries/System.Private.CoreLib/src/System/IO/Path.cs#L861
     /// </remarks>
@@ -277,7 +278,7 @@ public static string TruncateNameIfTooLong(string name)
     private static string TruncateName(string name, int length)
     {
         var removeTrailingCharsLength = name[length - 1] == EscapeChar ? 1 : (name[length - 2] == EscapeChar ? 2 : 0);
-        return name.Substring(0, length - removeTrailingCharsLength);
+        return name[..(length - removeTrailingCharsLength)];
     }
 
     /// <summary>
@@ -299,7 +300,7 @@ public static ulong GetHash(string str)
 
     public string ToPlatformPath()
     {
-        return Path.Combine(_pathSegments.Select(EscapeFilename).ToArray());
+        return Path.Combine([.. _pathSegments.Select(EscapeFilename)]);
     }
 
     public static FilePath FromPlatformPath(string path)
@@ -307,7 +308,7 @@ public static FilePath FromPlatformPath(string path)
         if (path == null)
             return new FilePath();
         var segments = path.Split(Path.DirectorySeparatorChar).Select(UnEscapeFilename);
-        return new FilePath(segments.ToArray());
+        return new FilePath(segments);
     }
 
     public static FilePath FromMsAppPath(string path)
@@ -323,21 +324,17 @@ public static FilePath ToFilePath(string path)
         if (path == null)
             return new FilePath();
         var segments = path.Split(Path.DirectorySeparatorChar).Select(x => x);
-        return new FilePath(segments.ToArray());
+        return new FilePath(segments);
     }
 
     public static FilePath RootedAt(string root, FilePath remainder)
     {
-        var segments = new List<string>() { root };
-        segments.AddRange(remainder._pathSegments);
-        return new FilePath(segments.ToArray());
+        return new FilePath(remainder._pathSegments.Prepend(root));
     }
 
     public FilePath Append(string segment)
     {
-        var newSegments = new List<string>(_pathSegments);
-        newSegments.Add(segment);
-        return new FilePath(newSegments.ToArray());
+        return new FilePath(_pathSegments.Append(segment));
     }
 
     public bool StartsWith(string root, StringComparison stringComparison)
@@ -402,8 +399,8 @@ public string HandleFileNameCollisions(string path)
         var suffixCounter = 0;
         var fileName = GetFileName();
         var extension = GetCustomExtension(fileName);
-        var fileNameWithoutExtension = fileName.Substring(0, fileName.Length - extension.Length);
-        var pathWithoutFileName = path.Substring(0, path.Length - fileName.Length);
+        var fileNameWithoutExtension = fileName[..^extension.Length];
+        var pathWithoutFileName = path[..^fileName.Length];
         while (File.Exists(path))
         {
             var filename = fileNameWithoutExtension + '_' + ++suffixCounter + extension;
diff --git a/src/PAModel/IR/IRNode.cs b/src/PAModel/IR/IRNode.cs
index 0a1b2f6e..8422f7b1 100644
--- a/src/PAModel/IR/IRNode.cs
+++ b/src/PAModel/IR/IRNode.cs
@@ -23,9 +23,9 @@ internal abstract class IRNode
 internal class BlockNode : IRNode, ICloneable<BlockNode>, IEquatable<BlockNode>
 {
     public TypedNameNode Name;
-    public IList<PropertyNode> Properties = new List<PropertyNode>();
-    public IList<FunctionNode> Functions = new List<FunctionNode>();
-    public IList<BlockNode> Children = new List<BlockNode>();
+    public IList<PropertyNode> Properties = [];
+    public IList<FunctionNode> Functions = [];
+    public IList<BlockNode> Children = [];
 
     public override void Accept<Context>(IRNodeVisitor<Context> visitor, Context context)
     {
@@ -196,8 +196,8 @@ public override int GetHashCode()
 internal class FunctionNode : IRNode, ICloneable<FunctionNode>, IEquatable<FunctionNode>
 {
     public string Identifier;
-    public IList<TypedNameNode> Args = new List<TypedNameNode>();
-    public IList<ArgMetadataBlockNode> Metadata = new List<ArgMetadataBlockNode>();
+    public IList<TypedNameNode> Args = [];
+    public IList<ArgMetadataBlockNode> Metadata = [];
 
     public override void Accept<Context>(IRNodeVisitor<Context> visitor, Context context)
     {
diff --git a/src/PAModel/IR/IRStateHelpers.cs b/src/PAModel/IR/IRStateHelpers.cs
index fde22114..3d35838d 100644
--- a/src/PAModel/IR/IRStateHelpers.cs
+++ b/src/PAModel/IR/IRStateHelpers.cs
@@ -50,8 +50,8 @@ private static void SplitIRAndState(Item control, string topParentName, int inde
                         customProp.PropertyScopeKey.PropertyScopeRulesKey);
 
                 // Skip component property params on instances
-                customPropsToHide = new HashSet<string>(customPropScopeRules
-                           .Select(propertyScopeRule => propertyScopeRule.Name));
+                customPropsToHide = [.. customPropScopeRules
+                           .Select(propertyScopeRule => propertyScopeRule.Name)];
 
                 foreach (var arg in customPropScopeRules)
                 {
@@ -61,7 +61,7 @@ private static void SplitIRAndState(Item control, string topParentName, int inde
                     if (invariantScript != null && invariantScript != arg.ScopeVariableInfo.DefaultRule)
                     {
                         var argKey = $"{control.Name}.{arg.Name}";
-                        entropy.FunctionParamsInvariantScriptsOnInstances.Add(argKey, new string[] { arg.ScopeVariableInfo.DefaultRule, invariantScript });
+                        entropy.FunctionParamsInvariantScriptsOnInstances.Add(argKey, [arg.ScopeVariableInfo.DefaultRule, invariantScript]);
                     }
                 }
             }
@@ -111,7 +111,7 @@ private static void SplitIRAndState(Item control, string topParentName, int inde
                         if (invariantScript != null && invariantScript != arg.ScopeVariableInfo.DefaultRule)
                         {
                             var argKey = $"{control.Name}.{arg.Name}";
-                            entropy.FunctionParamsInvariantScripts.Add(argKey, new string[] { arg.ScopeVariableInfo.DefaultRule, invariantScript });
+                            entropy.FunctionParamsInvariantScripts.Add(argKey, [arg.ScopeVariableInfo.DefaultRule, invariantScript]);
                         }
 
                         arg.ScopeVariableInfo.DefaultRule = null;
@@ -258,7 +258,7 @@ private static void SplitIRAndState(Item control, string topParentName, int inde
             Name = control.Name,
             TopParentName = topParentName,
             Properties = propStates,
-            DynamicProperties = dynPropStates.Any() ? dynPropStates : null,
+            DynamicProperties = dynPropStates.Count != 0 ? dynPropStates : null,
             HasDynamicProperties = control.HasDynamicProperties,
             StyleName = control.StyleName,
             IsGroupControl = control.IsGroupControl,
@@ -433,7 +433,7 @@ private static (Item item, int index) CombineIRAndState(BlockNode blockNode, Err
                 ControlUniqueId = uniqueId.ToString(),
                 VariantName = variantName ?? string.Empty,
                 Rules = properties.ToArray(),
-                DynamicProperties = (isInResponsiveLayout && dynamicProperties.Any()) ? dynamicProperties.ToArray() : null,
+                DynamicProperties = (isInResponsiveLayout && dynamicProperties.Count != 0) ? dynamicProperties.ToArray() : null,
                 HasDynamicProperties = state.HasDynamicProperties,
                 StyleName = state.StyleName,
                 ExtensionData = state.ExtensionData,
@@ -483,7 +483,7 @@ private static (Item item, int index) CombineIRAndState(BlockNode blockNode, Err
                 }
             }
             resultControlInfo.Rules = properties.ToArray();
-            var hasDynamicProperties = isInResponsiveLayout && dynamicProperties.Any();
+            var hasDynamicProperties = isInResponsiveLayout && dynamicProperties.Count != 0;
             resultControlInfo.DynamicProperties = hasDynamicProperties ? dynamicProperties.ToArray() : null;
             resultControlInfo.HasDynamicProperties = hasDynamicProperties;
             resultControlInfo.AllowAccessToGlobals = templateState?.ComponentManifest?.AllowAccessToGlobals;
diff --git a/src/PAModel/IR/UniqueIdRestorer.cs b/src/PAModel/IR/UniqueIdRestorer.cs
index 8574a3d1..0fb444d2 100644
--- a/src/PAModel/IR/UniqueIdRestorer.cs
+++ b/src/PAModel/IR/UniqueIdRestorer.cs
@@ -15,7 +15,7 @@ public UniqueIdRestorer(Entropy entropy)
     {
         _controlUniqueIds = entropy.ControlUniqueIds;
         _controlUniqueGuids = entropy.ControlUniqueGuids;
-        _nextId = (_controlUniqueIds.Any() ? Math.Max(2, _controlUniqueIds.Values.Max()) : 2) + 1;
+        _nextId = (_controlUniqueIds.Count != 0 ? Math.Max(2, _controlUniqueIds.Values.Max()) : 2) + 1;
     }
 
     public string GetControlId(string controlName)
diff --git a/src/PAModel/IsExternalInit.cs b/src/PAModel/IsExternalInit.cs
deleted file mode 100644
index c17deffc..00000000
--- a/src/PAModel/IsExternalInit.cs
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright (c) Microsoft Corporation.
-// Licensed under the MIT License.
-
-#if NETFRAMEWORK || NETSTANDARD2_0
-#pragma warning disable
-
-using System.ComponentModel;
-
-namespace System.Runtime.CompilerServices;
-
-// C# 9 init property setters and record types do not quite function out-of-the-box
-// for net4.8, but do so long as an "System.Runtime.CompilerServices.IsExternalInit"
-// type merely exists.
-[EditorBrowsable(EditorBrowsableState.Never)]
-#if TFMADAPTERS_PUBLIC
-public
-#else
-internal
-#endif
-static class IsExternalInit
-{
-}
-
-#pragma warning restore
-#endif
diff --git a/src/PAModel/MergeTool/ControlDiffVisitor.cs b/src/PAModel/MergeTool/ControlDiffVisitor.cs
index 0f33de0c..fe2fb40d 100644
--- a/src/PAModel/MergeTool/ControlDiffVisitor.cs
+++ b/src/PAModel/MergeTool/ControlDiffVisitor.cs
@@ -19,14 +19,14 @@ internal class ControlDiffVisitor : DefaultVisitor<ControlDiffContext>
     public static IEnumerable<IDelta> GetControlDelta(BlockNode ours, BlockNode parent, EditorStateStore childStateStore, TemplateStore parentTemplateStore, TemplateStore childTemplateStore, bool isInComponent)
     {
         var visitor = new ControlDiffVisitor(childStateStore, parentTemplateStore, childTemplateStore);
-        visitor.Visit(ours, new ControlDiffContext(new ControlPath(new List<string>()), parent, isInComponent));
+        visitor.Visit(ours, new ControlDiffContext(new ControlPath([]), parent, isInComponent));
 
         return visitor._deltas;
     }
 
     private ControlDiffVisitor(EditorStateStore childStateStore, TemplateStore parentTemplateStore, TemplateStore childTemplateStore)
     {
-        _deltas = new List<IDelta>();
+        _deltas = [];
         _childStateStore = childStateStore;
         _parentTemplateStore = parentTemplateStore;
         _childTemplateStore = childTemplateStore;
diff --git a/src/PAModel/Microsoft.PowerPlatform.Formulas.Tools.csproj b/src/PAModel/Microsoft.PowerPlatform.Formulas.Tools.csproj
index 0f0b6f40..2d32e4a3 100644
--- a/src/PAModel/Microsoft.PowerPlatform.Formulas.Tools.csproj
+++ b/src/PAModel/Microsoft.PowerPlatform.Formulas.Tools.csproj
@@ -1,7 +1,7 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>net48;net8.0;net10.0</TargetFrameworks>
-    <LangVersion>12</LangVersion>
+    <LangVersion>13</LangVersion>
 
     <SignAssembly>true</SignAssembly>
     <PublicSign>true</PublicSign>
@@ -22,8 +22,8 @@
   </PropertyGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net48'">
-    <PackageReference Include="System.IO.Compression" />
-    <PackageReference Include="System.Text.Json" />
+    <!-- Note: Since we're now including reference to Persistence.csproj, we don't need to manually include all of these. But we still need PolySharp since it's PrivateAssets="all" -->
+    <PackageReference Include="PolySharp" PrivateAssets="all" />
     <PackageReference Include="System.Text.Encodings.Web" />
   </ItemGroup>
 
@@ -32,11 +32,21 @@
     <PackageReference Include="YamlDotNet" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\Persistence\Microsoft.PowerPlatform.PowerApps.Persistence.csproj" />
+  </ItemGroup>
+
   <ItemGroup>
     <InternalsVisibleTo Include="PAModelTests" />
     <InternalsVisibleTo Include="PASopa" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Using Include="Microsoft.PowerPlatform.PowerApps.Persistence.TfmExtensions"/>
+    <Using Include="Microsoft.PowerPlatform.PowerApps.Persistence.TfmAdapters"/>
+    <Using Static="true" Include="Microsoft.PowerPlatform.PowerApps.Persistence.TfmAdapters.ThrowTfmAdapter"/>
+  </ItemGroup>
+
   <ItemGroup>
     <EmbeddedResource Include="ControlTemplates/commonStyleProperties.xml" />
     <EmbeddedResource Include="Themes/DefaultTheme.json" />
diff --git a/src/PAModel/PAConvert/ErrorContainer.cs b/src/PAModel/PAConvert/ErrorContainer.cs
index 40c7fcd6..e4a1298d 100644
--- a/src/PAModel/PAConvert/ErrorContainer.cs
+++ b/src/PAModel/PAConvert/ErrorContainer.cs
@@ -14,7 +14,7 @@ namespace Microsoft.PowerPlatform.Formulas.Tools;
 /// </summary>
 public class ErrorContainer : IEnumerable<Error>
 {
-    private readonly List<Error> _errors = new();
+    private readonly List<Error> _errors = [];
 
     internal void AddError(ErrorCode code, SourceLocation span, string errorMessage)
     {
diff --git a/src/PAModel/PAConvert/Parser/Parser.cs b/src/PAModel/PAConvert/Parser/Parser.cs
index 0978f55b..a86b444c 100644
--- a/src/PAModel/PAConvert/Parser/Parser.cs
+++ b/src/PAModel/PAConvert/Parser/Parser.cs
@@ -55,7 +55,7 @@ internal static bool TryParseControlDefCore(string line, out string ctrlName, ou
             return false;
         ctrlName = parsedIdent;
 
-        line = line.Substring(length);
+        line = line[length..];
         if (!line.StartsWith(" "))
             return false;
         line = line.TrimStart();
@@ -63,7 +63,7 @@ internal static bool TryParseControlDefCore(string line, out string ctrlName, ou
         if (!line.StartsWith("As "))
             return false;
 
-        line = line.Substring(2).TrimStart();
+        line = line[2..].TrimStart();
 
         if (!TryParseIdent(line, out parsedIdent, out length))
             return false;
@@ -73,10 +73,10 @@ internal static bool TryParseControlDefCore(string line, out string ctrlName, ou
         if (length == line.Length)
             return true;
 
-        line = line.Substring(length);
+        line = line[length..];
         if (!line.StartsWith("."))
             return false;
-        line = line.Substring(1);
+        line = line[1..];
 
         if (!TryParseIdent(line, out parsedIdent, out length))
             return false;
@@ -258,7 +258,7 @@ private FunctionNode ParseFunctionDef(YamlToken p)
         var funcName = m.Groups[1].Value;
         var functionNode = new FunctionNode() { Identifier = funcName };
 
-        line = line.Substring(m.Length);
+        line = line[m.Length..];
 
         m = paramRegex.Match(line);
         while (m.Success)
@@ -275,7 +275,7 @@ private FunctionNode ParseFunctionDef(YamlToken p)
                 }
             });
 
-            line = line.Substring(m.Length).TrimStart(',', ' ');
+            line = line[m.Length..].TrimStart(',', ' ');
             m = paramRegex.Match(line);
         }
 
@@ -343,7 +343,7 @@ private static bool IsControlStart(string line)
     {
         if (!TryParseIdent(line, out _, out var length))
             return false;
-        line = line.Substring(length).TrimStart();
+        line = line[length..].TrimStart();
         return line.StartsWith("As");
     }
 
diff --git a/src/PAModel/PAConvert/Parser/SourceLocation.cs b/src/PAModel/PAConvert/Parser/SourceLocation.cs
index aa8861f6..1cdf1e6b 100644
--- a/src/PAModel/PAConvert/Parser/SourceLocation.cs
+++ b/src/PAModel/PAConvert/Parser/SourceLocation.cs
@@ -6,27 +6,14 @@
 
 namespace Microsoft.PowerPlatform.Formulas.Tools.IR;
 
-internal readonly struct SourceLocation
+/// <summary>
+/// Indices into file are 1-based.
+/// </summary>
+internal readonly record struct SourceLocation(int StartLine, int StartChar, int EndLine, int EndChar, string FileName)
 {
-    public readonly int StartLine;
-    public readonly int StartChar;
-    public readonly int EndLine;
-    public readonly int EndChar;
-    public readonly string FileName;
-
-    // Indices into file are 1-based.
-    public SourceLocation(int startLine, int startChar, int endLine, int endChar, string fileName)
-    {
-        StartLine = startLine;
-        StartChar = startChar;
-        EndLine = endLine;
-        EndChar = endChar;
-        FileName = fileName;
-    }
-
     public static SourceLocation FromFile(string filename)
     {
-        return new SourceLocation(0, 0, 0, 0, filename);
+        return new(0, 0, 0, 0, filename);
     }
 
     public override string ToString()
@@ -84,19 +71,4 @@ public static SourceLocation FromChildren(List<SourceLocation> locations)
 
         return new SourceLocation(minLoc.StartLine, minLoc.StartChar, maxLoc.EndLine, maxLoc.EndChar, maxLoc.FileName);
     }
-
-    public override bool Equals(object obj)
-    {
-        return obj is SourceLocation other &&
-            other.FileName == FileName &&
-            other.StartChar == StartChar &&
-            other.StartLine == StartLine &&
-            other.EndChar == EndChar &&
-            other.EndLine == EndLine;
-    }
-
-    public override int GetHashCode()
-    {
-        return (FileName, StartChar, EndChar, StartLine, EndLine).GetHashCode();
-    }
 }
diff --git a/src/PAModel/PAConvert/Yaml/YamlLexer.cs b/src/PAModel/PAConvert/Yaml/YamlLexer.cs
index 0105d6e4..53eebbb2 100644
--- a/src/PAModel/PAConvert/Yaml/YamlLexer.cs
+++ b/src/PAModel/PAConvert/Yaml/YamlLexer.cs
@@ -16,7 +16,7 @@ namespace Microsoft.PowerPlatform.Formulas.Tools.Yaml;
 /// </summary>
 internal class YamlLexer : IDisposable
 {
-    private const string NewLine = "\n";
+    private const char NewLine = '\n';
 
     // The actual contents to read.
     private readonly TextReader _reader;
@@ -49,13 +49,12 @@ public YamlLexer(TextReader source, string filenameHint = null)
 
         // We pretend the file is wrapped in a "object:" tag.
         _lastPair = YamlToken.NewStartObj(SourceLocation.FromFile(_currentFileName), null);
-        _currentIndent =
-        [
+        _currentIndent = new([
             new() {
                 LineStart = 0,
                 OldIndentLevel = -1,
             }
-        ];
+        ]);
     }
 
     /// <summary>
@@ -264,7 +263,7 @@ private YamlToken ReadNextWorker()
         line.MaybeEat(':'); // skip colon.
 
         // Prop name could have spaces, but no colons.
-        var propName = line._line.Substring(indentLen, line._idx - indentLen - 1).Trim();
+        var propName = line.Line.Substring(indentLen, line._idx - indentLen - 1).Trim();
 
         if (requiresClosingDoubleQuote)
         {
@@ -321,7 +320,7 @@ private YamlToken ReadNextWorker()
             // Single line. Property doesn't include \n at end.
             value = line.RestOfLine;
 
-            if (value.IndexOf('#') >= 0)
+            if (value.Contains('#'))
             {
                 return UnsupportedComment(line);
             }
@@ -392,7 +391,7 @@ private YamlToken ReadNextWorker()
                 return Unsupported(line, "Property value must start with an '='");
             }
 
-            value = value.Substring(1); // move past '='
+            value = value[1..]; // move past '='
         }
         else if (Options.HasFlag(YamlLexerOptions.EnforceLeadingEquals))
         {
@@ -406,7 +405,7 @@ private YamlToken ReadNextWorker()
             MoveNextLine();
         }
 
-        var endIndex = line._line.Length + 1;
+        var endIndex = line.Line.Length + 1;
         return YamlToken.NewProperty(LocWorker(startColumn, endIndex), propName, value);
     }
 
@@ -419,7 +418,7 @@ private YamlToken Unsupported(LineParser line, string message)
 
     private YamlToken UnsupportedSingleQuote(LineParser line, bool isComponent)
     {
-        var lineSplit = line._line.ToString().ToLower().Split(new string[] { " as " }, StringSplitOptions.None);
+        var lineSplit = line.Line.ToLower().Split(" as ", StringSplitOptions.None);
 
         if (lineSplit.Length > 2)
         {
@@ -543,46 +542,19 @@ private string ReadMultiline(int multilineMode)
     // Helper for reading through a single line.
     // This treats EOL as (char) 0.
     [DebuggerDisplay("{DebuggerToString()}")]
-    private class LineParser
+    private class LineParser(string line)
     {
         // 0-based character index into line
         public int _idx;
 
-        public readonly string _line;
-
-        public LineParser(string line)
-        {
-            _line = line;
-        }
+        public readonly string Line = line;
 
         // Helper to handle eol.
-        public char Current
-        {
-            get
-            {
-                if (_idx >= _line.Length) { return (char)0; }
-                return _line[_idx];
-            }
-        }
-        public char Previous
-        {
-            get
-            {
-                if (_idx - 1 >= _line.Length || _idx - 1 < 0) { return (char)0; }
-                return _line[_idx - 1];
-            }
-        }
-
+        public char Current => _idx >= Line.Length ? (char)0 : Line[_idx];
 
-        public string RestOfLine
-        {
-            get
-            {
-                if (_idx >= _line.Length) return string.Empty;
-                return _line.Substring(_idx);
-            }
-        }
+        public char Previous => _idx - 1 >= Line.Length || _idx - 1 < 0 ? (char)0 : Line[_idx - 1];
 
+        public string RestOfLine => _idx >= Line.Length ? string.Empty : Line[_idx..];
 
         public bool MaybeEat(char ch)
         {
@@ -605,8 +577,8 @@ public int EatIndent()
         // Show '|' at _idx position
         private string DebuggerToString()
         {
-            var idx = Math.Min(_line.Length, _idx);
-            return _line.Substring(0, idx) + "¤" + _line.Substring(idx);
+            var idx = Math.Min(Line.Length, _idx);
+            return $"{Line[..idx]}¤{Line[idx..]}";
         }
     }
 
diff --git a/src/PAModel/PAConvert/Yaml/YamlWriter.cs b/src/PAModel/PAConvert/Yaml/YamlWriter.cs
index a7509873..d60b9fd2 100644
--- a/src/PAModel/PAConvert/Yaml/YamlWriter.cs
+++ b/src/PAModel/PAConvert/Yaml/YamlWriter.cs
@@ -32,8 +32,7 @@ public void WriteStartObject(string propertyName)
     {
         WriteIndent();
 
-        var needsEscape = propertyName.IndexOfAny(new char[] { '\"', '\'' }) != -1;
-        if (needsEscape)
+        if (propertyName.AsSpan().ContainsAny("\"'"))
             propertyName = $"\"{propertyName.Replace("\"", "\\\"")}\"";
 
         _textWriter.Write(propertyName);
@@ -106,7 +105,7 @@ public void WriteProperty(string propertyName, string value, bool includeEquals
 
         value = NormalizeNewlines(value);
 
-        var isSingleLine = value.IndexOfAny(new char[] { '#', '\n', ':' }) == -1;
+        var isSingleLine = value.IndexOfAny(['#', '\n', ':']) == -1;
 
         // For consistency, both single and multiline PA properties prefix with '='.
         // Only single-line actually needs this - to avoid yaml's regular expression escaping.
diff --git a/src/PAModel/Schemas/DataComponentDefinitionJson.cs b/src/PAModel/Schemas/DataComponentDefinitionJson.cs
index c494a508..15167a90 100644
--- a/src/PAModel/Schemas/DataComponentDefinitionJson.cs
+++ b/src/PAModel/Schemas/DataComponentDefinitionJson.cs
@@ -88,8 +88,10 @@ public ComponentDefinitionInfoJson(ControlInfoJson.Item item, string timestamp,
         // Once ControlPropertyState has an actual schema, this can be cleaned up.
         if (item.ExtensionData.ContainsKey("ControlPropertyState"))
         {
-            ExtensionData = new Dictionary<string, object>();
-            ExtensionData["ControlPropertyState"] = item.ExtensionData["ControlPropertyState"];
+            ExtensionData = new Dictionary<string, object>
+            {
+                ["ControlPropertyState"] = item.ExtensionData["ControlPropertyState"]
+            };
         }
     }
 }
diff --git a/src/PAModel/Schemas/DocumentPropertiesJson.cs b/src/PAModel/Schemas/DocumentPropertiesJson.cs
index 4603a8c4..9de2dcde 100644
--- a/src/PAModel/Schemas/DocumentPropertiesJson.cs
+++ b/src/PAModel/Schemas/DocumentPropertiesJson.cs
@@ -71,7 +71,7 @@ public static DocumentPropertiesJson CreateDefault(string name)
             Author = "",
             FileID = Guid.NewGuid().ToString(),
             Id = Guid.NewGuid().ToString(),
-            ControlCount = new Dictionary<SomeEnum, int>(),
+            ControlCount = [],
             DefaultConnectedDataSourceMaxGetRowsCount = 500,
             DocumentAppType = AppType.DesktopOrTablet,
 
@@ -96,8 +96,8 @@ public static DocumentPropertiesJson CreateDefault(string name)
 
     private static string[] GetAppPreviewFlagDefault()
     {
-        return new string[]
-        {
+        return
+        [
           "delayloadscreens",
           "blockmovingcontrol",
           "projectionmapping",
@@ -116,7 +116,7 @@ private static string[] GetAppPreviewFlagDefault()
           "aibuilderserviceenrollment",
           "enablesummerlandgeospatialfeatures",
           "enablesummerlandmixedrealityfeatures"
-        };
+        ];
     }
 }
 
diff --git a/src/PAModel/Schemas/PcfControls/PcfControl.cs b/src/PAModel/Schemas/PcfControls/PcfControl.cs
index 9877de07..d4a1acf0 100644
--- a/src/PAModel/Schemas/PcfControls/PcfControl.cs
+++ b/src/PAModel/Schemas/PcfControls/PcfControl.cs
@@ -95,7 +95,7 @@ internal static string GenerateDynamicControlDefinition(PcfControl control)
         _dynamicControlDefinition.SubscribedFunctionalities = control.SubscribedFunctionalities != null ? JsonSerializer.Serialize(control.SubscribedFunctionalities, jsonOptions) : null;
         _dynamicControlDefinition.AuthConfigProperties = control.AuthConfigProperties != null ? JsonSerializer.Serialize(control.AuthConfigProperties, jsonOptions) : null;
         _dynamicControlDefinition.DataConnectors = control.DataConnectors != null ? JsonSerializer.Serialize(control.DataConnectors, jsonOptions) : null;
-        _dynamicControlDefinition.ExtensionData = control.ExtensionData ?? new Dictionary<string, object>();
+        _dynamicControlDefinition.ExtensionData = control.ExtensionData ?? [];
 
         return JsonExtensions.JsonSerialize(_dynamicControlDefinition);
     }
diff --git a/src/PAModel/Schemas/ResourcesJson.cs b/src/PAModel/Schemas/ResourcesJson.cs
index 78bcdba2..18b23bdf 100644
--- a/src/PAModel/Schemas/ResourcesJson.cs
+++ b/src/PAModel/Schemas/ResourcesJson.cs
@@ -66,7 +66,7 @@ internal class ResourceJson
 
     public FilePath GetPath()
     {
-        var resourceName = Path.Substring("Assets\\".Length);
+        var resourceName = Path["Assets\\".Length..];
         var path = FilePath.FromMsAppPath(resourceName);
         return path;
     }
diff --git a/src/PAModel/Schemas/adhoc/CanvasManifestJson.cs b/src/PAModel/Schemas/adhoc/CanvasManifestJson.cs
index 2d333a3f..1a7ecf0c 100644
--- a/src/PAModel/Schemas/adhoc/CanvasManifestJson.cs
+++ b/src/PAModel/Schemas/adhoc/CanvasManifestJson.cs
@@ -21,5 +21,5 @@ internal class CanvasManifestJson
     // Logo file
     // $$$ Other files?
     public PublishInfoJson PublishInfo { get; set; }
-    public List<string> ScreenOrder { get; set; } = new List<string>();
+    public List<string> ScreenOrder { get; set; } = [];
 }
diff --git a/src/PAModel/Schemas/adhoc/Control.cs b/src/PAModel/Schemas/adhoc/Control.cs
index 8769b3d0..72ce5a8f 100644
--- a/src/PAModel/Schemas/adhoc/Control.cs
+++ b/src/PAModel/Schemas/adhoc/Control.cs
@@ -93,11 +93,13 @@ public static Template CreateDefaultTemplate(string name, ControlTemplate contro
                 template.Version = controlTemplate.Version;
                 template.IsComponentDefinition = false;
                 template.LastModifiedTimestamp = "0";
-                template.ExtensionData = new Dictionary<string, object>();
-                template.ExtensionData.Add("FirstParty", true);
-                template.ExtensionData.Add("IsCustomGroupControlTemplate", false);
-                template.ExtensionData.Add("CustomGroupControlTemplateName", "");
-                template.ExtensionData.Add("OverridableProperties", new object());
+                template.ExtensionData = new Dictionary<string, object>
+                {
+                    { "FirstParty", true },
+                    { "IsCustomGroupControlTemplate", false },
+                    { "CustomGroupControlTemplateName", "" },
+                    { "OverridableProperties", new object() }
+                };
             }
             return template;
         }
@@ -173,14 +175,16 @@ public static Item CreateDefaultControl(ControlTemplate templateDefault = null)
 
         public static Dictionary<string, object> CreateDefaultExtensionData()
         {
-            var extensionData = new Dictionary<string, object>();
-            extensionData.Add("LayoutName", "");
-            extensionData.Add("MetaDataIDKey", "");
-            extensionData.Add("PersistMetaDataIDKey", false);
-            extensionData.Add("IsFromScreenLayout", false);
-            extensionData.Add("IsDataControl", false);
-            extensionData.Add("IsAutoGenerated", false);
-            extensionData.Add("IsLocked", false);
+            var extensionData = new Dictionary<string, object>
+            {
+                { "LayoutName", "" },
+                { "MetaDataIDKey", "" },
+                { "PersistMetaDataIDKey", false },
+                { "IsFromScreenLayout", false },
+                { "IsDataControl", false },
+                { "IsAutoGenerated", false },
+                { "IsLocked", false }
+            };
             return extensionData;
         }
     }
diff --git a/src/PAModel/Serializers/MsAppSerializer.cs b/src/PAModel/Serializers/MsAppSerializer.cs
index 1df71654..ef56969a 100644
--- a/src/PAModel/Serializers/MsAppSerializer.cs
+++ b/src/PAModel/Serializers/MsAppSerializer.cs
@@ -122,7 +122,7 @@ public static CanvasDocument Load(Stream streamToMsapp, ErrorContainer errors)
                         break;
 
                     case FileKind.Asset:
-                        app.AddAssetFile(FileEntry.FromZip(entry, name: fullName.Substring("Assets\\".Length)));
+                        app.AddAssetFile(FileEntry.FromZip(entry, name: fullName["Assets\\".Length..]));
                         break;
 
                     case FileKind.Checksum:
@@ -675,7 +675,7 @@ private static IEnumerable<FileEntry> GetMsAppFiles(this CanvasDocument app, Err
 
 
         var idRestorer = new UniqueIdRestorer(app._entropy);
-        var maxPublishOrderIndex = app._entropy.PublishOrderIndices.Any() ? app._entropy.PublishOrderIndices.Values.Max() : 0;
+        var maxPublishOrderIndex = app._entropy.PublishOrderIndices.Count != 0 ? app._entropy.PublishOrderIndices.Values.Max() : 0;
         // Rehydrate sources before yielding any to be written, processing component definitions first
         foreach (var controlData in app._screens.Concat(app._components)
             .OrderBy(source =>
@@ -724,7 +724,7 @@ private static IEnumerable<FileEntry> GetMsAppFiles(this CanvasDocument app, Err
             }
         }
 
-        RepairComponentInstanceIndex(app._entropy?.ComponentIndexes ?? new Dictionary<string, double>(), sourceFiles);
+        RepairComponentInstanceIndex(app._entropy?.ComponentIndexes ?? [], sourceFiles);
 
 
         // This ordering is essential, we need to match the order in which Studio writes the files to replicate certain order-dependent behavior.
@@ -746,7 +746,7 @@ private static IEnumerable<FileEntry> GetMsAppFiles(this CanvasDocument app, Err
         var pcfTemplates = app._templates.PcfTemplates ?? Array.Empty<PcfTemplateJson>();
         app._templates = new TemplatesJson()
         {
-            ComponentTemplates = componentTemplates.Any() ? componentTemplates.OrderBy(app._entropy.GetComponentOrder).ToArray() : null,
+            ComponentTemplates = componentTemplates.Count != 0 ? componentTemplates.OrderBy(app._entropy.GetComponentOrder).ToArray() : null,
             UsedTemplates = app._templates.UsedTemplates.OrderBy(app._entropy.GetOrder).ToArray(),
             PcfTemplates = pcfTemplates.Any() ? pcfTemplates.OrderBy(app._entropy.GetPcfVersioning).ToArray() : null
         };
@@ -921,7 +921,7 @@ internal static FileEntry ToFile<T>(FileKind kind, T value)
         }
         else
         {
-            var jsonStr = JsonSerializer.Serialize(value, JsonExtensions._jsonOpts);
+            var jsonStr = JsonSerializer.Serialize(value, JsonExtensions.JsonOpts);
 
             output = JsonNormalizer.Normalize(jsonStr);
         }
diff --git a/src/PAModel/Serializers/SourceSerializer.cs b/src/PAModel/Serializers/SourceSerializer.cs
index 2c8e87e0..02feb14e 100644
--- a/src/PAModel/Serializers/SourceSerializer.cs
+++ b/src/PAModel/Serializers/SourceSerializer.cs
@@ -307,12 +307,12 @@ public static CanvasDocument Create(string appName, string packagesPath, IList<s
 
     private static void LoadTemplateFiles(ErrorContainer errors, CanvasDocument app, string packagesPath, out Dictionary<string, ControlTemplate> loadedTemplates)
     {
-        loadedTemplates = new Dictionary<string, ControlTemplate>();
+        loadedTemplates = [];
         var templateList = new List<TemplatesJson.TemplateJson>();
         foreach (var file in new DirectoryReader(packagesPath).EnumerateFiles(string.Empty, "*.xml", searchSubdirectories: false))
         {
             var xmlContents = file.GetContents();
-            var templateNameFromFile = file._relativeName.Substring(0, file._relativeName.LastIndexOf('_'));
+            var templateNameFromFile = file._relativeName[..file._relativeName.LastIndexOf('_')];
             if (!ControlTemplateParser.TryParseTemplate(new TemplateStore(), xmlContents, app._properties.DocumentAppType, loadedTemplates, out var parsedTemplate, out var templateName, templateNameFromFile))
             {
                 errors.GenericError($"Unable to parse template file {file._relativeName}");
@@ -675,7 +675,7 @@ public static void SaveAsSource(CanvasDocument app, string directory2, ErrorCont
 
     private static void WriteDataSources(DirectoryWriter dir, CanvasDocument app, ErrorContainer errors)
     {
-        var untrackedLdr = app._dataSourceReferences?.Select(x => x.Key)?.ToList() ?? new List<string>();
+        var untrackedLdr = app._dataSourceReferences?.Select(x => x.Key)?.ToList() ?? [];
 
         // Data Sources  - write out each individual source.
         var filenames = new HashSet<string>();
@@ -751,7 +751,7 @@ private static void WriteDataSources(DirectoryWriter dir, CanvasDocument app, Er
                     }
                     if (ds.WadlMetadata.SwaggerJson != null)
                     {
-                        dir.WriteAllJson(SwaggerPackageDir, new FilePath(filename), JsonSerializer.Deserialize<SwaggerDefinition>(ds.WadlMetadata.SwaggerJson, JsonExtensions._jsonOpts));
+                        dir.WriteAllJson(SwaggerPackageDir, new FilePath(filename), JsonSerializer.Deserialize<SwaggerDefinition>(ds.WadlMetadata.SwaggerJson, JsonExtensions.JsonOpts));
                     }
                     ds.WadlMetadata = null;
                 }
@@ -890,7 +890,7 @@ private static void LoadDataSources(CanvasDocument app, DirectoryReader director
                 // now that we have seen first non null LocalReferenceDSJson
                 // we know for sure that dataSources for the localDatabaseReferenceJson was not null
                 // in that case, no longer assume dataSource to be null
-                localDatabaseReferenceJson.dataSources ??= new Dictionary<string, LocalDatabaseReferenceDataSource>();
+                localDatabaseReferenceJson.dataSources ??= [];
                 localDatabaseReferenceJson.dataSources?.Add(tableDef.EntityName, tableDef.LocalReferenceDSJson);
             }
         }
@@ -926,7 +926,7 @@ private static void LoadDataSources(CanvasDocument app, DirectoryReader director
                     {
                         case "NativeCDSDataSourceInfo":
                             ds.DatasetName = definition.DatasetName;
-                            ds.TableDefinition = JsonSerializer.Serialize(definition.TableDefinition, JsonExtensions._jsonOpts);
+                            ds.TableDefinition = JsonSerializer.Serialize(definition.TableDefinition, JsonExtensions.JsonOpts);
                             break;
                         case "ConnectedDataSourceInfo":
                             ds.DataEntityMetadataJson = definition.DataEntityMetadataJson;
@@ -971,7 +971,7 @@ private static void TrimViewNames(IEnumerable<DataSourceEntry> dataSourceEntries
         {
             if (ds.Name.StartsWith(dataSetName))
             {
-                ds.Name = ds.Name.Substring(dataSetName.Length);
+                ds.Name = ds.Name[dataSetName.Length..];
                 ds.TrimmedViewName = true;
             }
         }
@@ -1012,7 +1012,7 @@ private static void WriteTopParent(
         {
             foreach (var child in ir.Children)
             {
-                WriteTopParent(dir, app, child.Properties.FirstOrDefault(x => x.Identifier == "DisplayName").Expression.Expression.Trim(new char[] { '"' }), child, subDir, controlName);
+                WriteTopParent(dir, app, child.Properties.FirstOrDefault(x => x.Identifier == "DisplayName").Expression.Expression.Trim(['"']), child, subDir, controlName);
             }
 
             // Clear the children since they have already been sharded into their individual files.
@@ -1059,7 +1059,7 @@ private static void AddDefaultTheme(CanvasDocument app)
 
         var jsonString = reader.ReadToEnd();
 
-        app._themes = JsonSerializer.Deserialize<ThemesJson>(jsonString, JsonExtensions._jsonOpts);
+        app._themes = JsonSerializer.Deserialize<ThemesJson>(jsonString, JsonExtensions.JsonOpts);
     }
 
     private static BuildVerJson GetBuildDetails()
@@ -1076,7 +1076,7 @@ private static BuildVerJson GetBuildDetails()
             using var reader = new StreamReader(stream);
             var jsonString = reader.ReadToEnd();
 
-            return JsonSerializer.Deserialize<BuildVerJson>(jsonString, JsonExtensions._jsonOpts);
+            return JsonSerializer.Deserialize<BuildVerJson>(jsonString, JsonExtensions.JsonOpts);
         }
         catch (Exception)
         {
diff --git a/src/PAModel/SourceTransforms/AppTestTransform.cs b/src/PAModel/SourceTransforms/AppTestTransform.cs
index 4c3a46f4..04ec6690 100644
--- a/src/PAModel/SourceTransforms/AppTestTransform.cs
+++ b/src/PAModel/SourceTransforms/AppTestTransform.cs
@@ -241,6 +241,6 @@ public void BeforeWrite(BlockNode control)
                 Identifier = _metadataPropName
             });
         }
-        control.Children = new List<BlockNode>();
+        control.Children = [];
     }
 }
diff --git a/src/PAModel/SourceTransforms/ComponentInstanceTransform.cs b/src/PAModel/SourceTransforms/ComponentInstanceTransform.cs
index a6213cc2..dc272b38 100644
--- a/src/PAModel/SourceTransforms/ComponentInstanceTransform.cs
+++ b/src/PAModel/SourceTransforms/ComponentInstanceTransform.cs
@@ -10,7 +10,7 @@ internal class ComponentInstanceTransform : IControlTemplateTransform
     // Key is name in source, value is name in target
     // For AfterRead, that's ComponentID => ComponentName
     // For BeforeWrite, that's ComponentName => ComponentID
-    internal Dictionary<string, string> ComponentRenames = new();
+    internal Dictionary<string, string> ComponentRenames = [];
     private readonly ErrorContainer _errors;
 
     public ComponentInstanceTransform(ErrorContainer errors)
diff --git a/src/PAModel/SourceTransforms/DefaultValuesTransform.cs b/src/PAModel/SourceTransforms/DefaultValuesTransform.cs
index 82ed9158..c541e287 100644
--- a/src/PAModel/SourceTransforms/DefaultValuesTransform.cs
+++ b/src/PAModel/SourceTransforms/DefaultValuesTransform.cs
@@ -58,8 +58,8 @@ public void BeforeWrite(BlockNode node, bool inResponsiveContext)
         if (_controlStore.TryGetControlState(controlName, out var controlState) && controlState.Properties != null)
         {
             styleName = controlState.StyleName;
-            propNames = new HashSet<string>(controlState.Properties.Select(state => state.PropertyName)
-                .Concat(controlState.DynamicProperties?.Where(state => state.Property != null).Select(state => state.PropertyName) ?? Enumerable.Empty<string>()));
+            propNames = [.. controlState.Properties.Select(state => state.PropertyName)
+                .Concat(controlState.DynamicProperties?.Where(state => state.Property != null).Select(state => state.PropertyName) ?? Enumerable.Empty<string>())];
         }
 
         if (!_templateStore.TryGetValue(templateName, out var template))
diff --git a/src/PAModel/SourceTransforms/GalleryTemplateTransform.cs b/src/PAModel/SourceTransforms/GalleryTemplateTransform.cs
index dc3a10e7..cbac6246 100644
--- a/src/PAModel/SourceTransforms/GalleryTemplateTransform.cs
+++ b/src/PAModel/SourceTransforms/GalleryTemplateTransform.cs
@@ -65,8 +65,8 @@ public void BeforeWrite(BlockNode control)
                     TypeName = _childTemplateName
                 }
             },
-            Children = new List<BlockNode>(),
-            Functions = new List<FunctionNode>(),
+            Children = [],
+            Functions = [],
             Properties = childRules
         };
 
diff --git a/src/PAModel/SourceTransforms/GroupControlTransform.cs b/src/PAModel/SourceTransforms/GroupControlTransform.cs
index 3796ee97..277d8dbe 100644
--- a/src/PAModel/SourceTransforms/GroupControlTransform.cs
+++ b/src/PAModel/SourceTransforms/GroupControlTransform.cs
@@ -34,7 +34,7 @@ public GroupControlTransform(ErrorContainer errors, EditorStateStore editorState
     public void AfterRead(BlockNode control)
     {
         var groupControls = GetGroupControlChildren(control);
-        if (!groupControls.Any())
+        if (groupControls.Count == 0)
             return;
 
         var peerControlsDict = control.Children.ToDictionary(peer => peer.Name.Identifier, peer => peer);
@@ -74,7 +74,7 @@ public void AfterRead(BlockNode control)
     public void BeforeWrite(BlockNode control)
     {
         var groupControls = GetGroupControlChildren(control);
-        if (!groupControls.Any())
+        if (groupControls.Count == 0)
             return;
 
         foreach (var groupControl in groupControls)
@@ -102,7 +102,7 @@ public void BeforeWrite(BlockNode control)
             {
                 control.Children.Add(child);
             }
-            groupControl.Children = new List<BlockNode>();
+            groupControl.Children = [];
             groupControlState.GroupedControlsKey = groupedControlNames.ToList();
         }
     }
diff --git a/src/PAModel/SourceTransforms/SourceTransformer.cs b/src/PAModel/SourceTransforms/SourceTransformer.cs
index 72b04242..817c3b17 100644
--- a/src/PAModel/SourceTransforms/SourceTransformer.cs
+++ b/src/PAModel/SourceTransforms/SourceTransformer.cs
@@ -29,10 +29,12 @@ public SourceTransformer(
         TemplateStore templateStore,
         Entropy entropy)
     {
-        _templateTransforms = new List<IControlTemplateTransform>();
-        _templateTransforms.Add(new GalleryTemplateTransform(defaultValueTemplates, stateStore));
-        _templateTransforms.Add(new AppTestTransform(app, errors, templateStore, stateStore, entropy));
-        _templateTransforms.Add(componentInstanceTransform);
+        _templateTransforms =
+        [
+            new GalleryTemplateTransform(defaultValueTemplates, stateStore),
+            new AppTestTransform(app, errors, templateStore, stateStore, entropy),
+            componentInstanceTransform,
+        ];
 
         _groupControlTransform = new GroupControlTransform(errors, stateStore, entropy);
 
diff --git a/src/PAModel/packages.lock.json b/src/PAModel/packages.lock.json
index 09f295cd..a8cc0678 100644
--- a/src/PAModel/packages.lock.json
+++ b/src/PAModel/packages.lock.json
@@ -8,11 +8,11 @@
         "resolved": "13.0.3",
         "contentHash": "HrC5BXdl00IP9zeV+0Z848QWPAoCr9P3bDEZguI+gkLcBKAOxix/tLEAAHC+UvDNPv4a2d18lOReHMOagPa+zQ=="
       },
-      "System.IO.Compression": {
+      "PolySharp": {
         "type": "Direct",
-        "requested": "[4.3.0, )",
-        "resolved": "4.3.0",
-        "contentHash": "YHndyoiV90iu4iKG115ibkhrG+S3jBm8Ap9OwoUAzO5oPDAWcr0SFwQFm0HjM8WkEZWo0zvLTyLmbvTkW1bXgg=="
+        "requested": "[1.15.0, )",
+        "resolved": "1.15.0",
+        "contentHash": "FbU0El+EEjdpuIX4iDbeS7ki1uzpJPx8vbqOzEtqnl1GZeAGJfq+jCbxeJL2y0EPnUNk8dRnnqR2xnYXg9Tf+g=="
       },
       "System.Text.Encodings.Web": {
         "type": "Direct",
@@ -25,22 +25,6 @@
           "System.Runtime.CompilerServices.Unsafe": "6.1.2"
         }
       },
-      "System.Text.Json": {
-        "type": "Direct",
-        "requested": "[10.0.7, )",
-        "resolved": "10.0.7",
-        "contentHash": "F8Pu2QLUMeniVbtiyk7n7LCfFYxlcJ8ASaSwglJyq6dxa34iCQrikQszsgJClIJWuSWjcyhKkV7daAzYJqeVwA==",
-        "dependencies": {
-          "Microsoft.Bcl.AsyncInterfaces": "10.0.7",
-          "System.Buffers": "4.6.1",
-          "System.IO.Pipelines": "10.0.7",
-          "System.Memory": "4.6.3",
-          "System.Runtime.CompilerServices.Unsafe": "6.1.2",
-          "System.Text.Encodings.Web": "10.0.7",
-          "System.Threading.Tasks.Extensions": "4.6.3",
-          "System.ValueTuple": "4.6.2"
-        }
-      },
       "YamlDotNet": {
         "type": "Direct",
         "requested": "[17.1.0, )",
@@ -60,6 +44,15 @@
         "resolved": "4.6.1",
         "contentHash": "N8GXpmiLMtljq7gwvyS+1QvKT/W2J8sNAvx+HVg4NGmsG/H+2k/y9QI23auLJRterrzCiDH+IWAw4V/GPwsMlw=="
       },
+      "System.Diagnostics.DiagnosticSource": {
+        "type": "Transitive",
+        "resolved": "10.0.7",
+        "contentHash": "Fu6AxFf9bHz/Q7DQmxKC0o+UgFes8bs2Xh+PH/x31yExRAOASTwlzjZsISTtqVU5gQshKHLZopxEBTaIyfv0wg==",
+        "dependencies": {
+          "System.Memory": "4.6.3",
+          "System.Runtime.CompilerServices.Unsafe": "6.1.2"
+        }
+      },
       "System.IO.Pipelines": {
         "type": "Transitive",
         "resolved": "10.0.7",
@@ -85,6 +78,57 @@
         "resolved": "4.6.2",
         "contentHash": "yQgmjfFximrNm9LIV3mL6T5MzjeC+epeE5rl4hXxAlYmxby7RM1dPSkIKXk9HNkl6G54h2JHOmLD46+Pey+IRg=="
       },
+      "microsoft.powerplatform.powerapps.persistence": {
+        "type": "Project",
+        "dependencies": {
+          "Microsoft.Extensions.DependencyInjection.Abstractions": "[10.0.7, )",
+          "Microsoft.Extensions.Logging.Abstractions": "[10.0.7, )",
+          "System.Collections.Immutable": "[10.0.7, )",
+          "System.IO.Compression": "[4.3.0, )",
+          "System.Memory": "[4.6.3, )",
+          "System.Text.Json": "[10.0.7, )",
+          "System.Threading.Tasks.Extensions": "[4.6.3, )",
+          "YamlDotNet": "[17.1.0, )"
+        }
+      },
+      "Microsoft.Extensions.DependencyInjection.Abstractions": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "Z6mfFEaFcwCfSboxJwOLfu7/31npCY9q70WUamHW/vRQhDvBKOT4Vf9YkZj5J6hLvJpb0oDEYfHunQZj0xxvKw==",
+        "dependencies": {
+          "Microsoft.Bcl.AsyncInterfaces": "10.0.7",
+          "System.Threading.Tasks.Extensions": "4.6.3"
+        }
+      },
+      "Microsoft.Extensions.Logging.Abstractions": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "tIEcQ2gvERrH2KiCjdsVcHGhXt9lIsuDStfOIeZWr7/fP8IXhGiYfx0/80PNI7WPO2IYuFtlZLSlnTS8+/Mchw==",
+        "dependencies": {
+          "Microsoft.Extensions.DependencyInjection.Abstractions": "10.0.7",
+          "System.Buffers": "4.6.1",
+          "System.Diagnostics.DiagnosticSource": "10.0.7",
+          "System.Memory": "4.6.3"
+        }
+      },
+      "System.Collections.Immutable": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "0Ti4Jv1ga3eurH5HaCVsPybcBl+08YfzM9smqAJzHvqV494xK+0pSbytGrMTWhph+zsyKIaoGNiR5u3by5bj+A==",
+        "dependencies": {
+          "System.Memory": "4.6.3",
+          "System.Runtime.CompilerServices.Unsafe": "6.1.2"
+        }
+      },
+      "System.IO.Compression": {
+        "type": "CentralTransitive",
+        "requested": "[4.3.0, )",
+        "resolved": "4.3.0",
+        "contentHash": "YHndyoiV90iu4iKG115ibkhrG+S3jBm8Ap9OwoUAzO5oPDAWcr0SFwQFm0HjM8WkEZWo0zvLTyLmbvTkW1bXgg=="
+      },
       "System.Memory": {
         "type": "CentralTransitive",
         "requested": "[4.6.3, )",
@@ -96,6 +140,22 @@
           "System.Runtime.CompilerServices.Unsafe": "6.1.2"
         }
       },
+      "System.Text.Json": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "F8Pu2QLUMeniVbtiyk7n7LCfFYxlcJ8ASaSwglJyq6dxa34iCQrikQszsgJClIJWuSWjcyhKkV7daAzYJqeVwA==",
+        "dependencies": {
+          "Microsoft.Bcl.AsyncInterfaces": "10.0.7",
+          "System.Buffers": "4.6.1",
+          "System.IO.Pipelines": "10.0.7",
+          "System.Memory": "4.6.3",
+          "System.Runtime.CompilerServices.Unsafe": "6.1.2",
+          "System.Text.Encodings.Web": "10.0.7",
+          "System.Threading.Tasks.Extensions": "4.6.3",
+          "System.ValueTuple": "4.6.2"
+        }
+      },
       "System.Threading.Tasks.Extensions": {
         "type": "CentralTransitive",
         "requested": "[4.6.3, )",
@@ -118,6 +178,29 @@
         "requested": "[17.1.0, )",
         "resolved": "17.1.0",
         "contentHash": "AhsNXgeAs3Ugt653t8LC44xXDuldFfwBpWbWX9pN3e4Yg8U5Bk8jLn8eXtGv5HV2V2nHu7F46fqsPC+tpcTGAA=="
+      },
+      "microsoft.powerplatform.powerapps.persistence": {
+        "type": "Project",
+        "dependencies": {
+          "Microsoft.Extensions.DependencyInjection.Abstractions": "[10.0.7, )",
+          "Microsoft.Extensions.Logging.Abstractions": "[10.0.7, )",
+          "YamlDotNet": "[17.1.0, )"
+        }
+      },
+      "Microsoft.Extensions.DependencyInjection.Abstractions": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "Z6mfFEaFcwCfSboxJwOLfu7/31npCY9q70WUamHW/vRQhDvBKOT4Vf9YkZj5J6hLvJpb0oDEYfHunQZj0xxvKw=="
+      },
+      "Microsoft.Extensions.Logging.Abstractions": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "tIEcQ2gvERrH2KiCjdsVcHGhXt9lIsuDStfOIeZWr7/fP8IXhGiYfx0/80PNI7WPO2IYuFtlZLSlnTS8+/Mchw==",
+        "dependencies": {
+          "Microsoft.Extensions.DependencyInjection.Abstractions": "10.0.7"
+        }
       }
     },
     "net8.0": {
@@ -132,6 +215,35 @@
         "requested": "[17.1.0, )",
         "resolved": "17.1.0",
         "contentHash": "AhsNXgeAs3Ugt653t8LC44xXDuldFfwBpWbWX9pN3e4Yg8U5Bk8jLn8eXtGv5HV2V2nHu7F46fqsPC+tpcTGAA=="
+      },
+      "System.Diagnostics.DiagnosticSource": {
+        "type": "Transitive",
+        "resolved": "10.0.7",
+        "contentHash": "Fu6AxFf9bHz/Q7DQmxKC0o+UgFes8bs2Xh+PH/x31yExRAOASTwlzjZsISTtqVU5gQshKHLZopxEBTaIyfv0wg=="
+      },
+      "microsoft.powerplatform.powerapps.persistence": {
+        "type": "Project",
+        "dependencies": {
+          "Microsoft.Extensions.DependencyInjection.Abstractions": "[10.0.7, )",
+          "Microsoft.Extensions.Logging.Abstractions": "[10.0.7, )",
+          "YamlDotNet": "[17.1.0, )"
+        }
+      },
+      "Microsoft.Extensions.DependencyInjection.Abstractions": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "Z6mfFEaFcwCfSboxJwOLfu7/31npCY9q70WUamHW/vRQhDvBKOT4Vf9YkZj5J6hLvJpb0oDEYfHunQZj0xxvKw=="
+      },
+      "Microsoft.Extensions.Logging.Abstractions": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "tIEcQ2gvERrH2KiCjdsVcHGhXt9lIsuDStfOIeZWr7/fP8IXhGiYfx0/80PNI7WPO2IYuFtlZLSlnTS8+/Mchw==",
+        "dependencies": {
+          "Microsoft.Extensions.DependencyInjection.Abstractions": "10.0.7",
+          "System.Diagnostics.DiagnosticSource": "10.0.7"
+        }
       }
     }
   }
diff --git a/src/PAModelTests/.editorconfig b/src/PAModelTests/.editorconfig
deleted file mode 100644
index bf31e936..00000000
--- a/src/PAModelTests/.editorconfig
+++ /dev/null
@@ -1,9 +0,0 @@
-[*.cs]
-
-# Category overries:
-# Disabling these categories because the original implementation didn't have them on and we're not making changes to it at this time.
-dotnet_analyzer_diagnostic.category-Globalization.severity    = silent
-dotnet_analyzer_diagnostic.category-Performance.severity      = silent
-dotnet_analyzer_diagnostic.category-Usage.severity            = silent
-
-# Rule overrides:
diff --git a/src/PAModelTests/PAModelTests.csproj b/src/PAModelTests/PAModelTests.csproj
index 840c197f..8f802f8b 100644
--- a/src/PAModelTests/PAModelTests.csproj
+++ b/src/PAModelTests/PAModelTests.csproj
@@ -2,11 +2,15 @@
   <!-- https://learn.microsoft.com/en-us/dotnet/core/testing/unit-testing-mstest-sdk -->
   <PropertyGroup>
     <TargetFrameworks>net48;net8.0;net10.0</TargetFrameworks>
-    <LangVersion Condition="'$(TargetFramework)' == 'net48'">10.0</LangVersion>
+    <LangVersion>13</LangVersion>
     <SignAssembly>true</SignAssembly>
     <PublicSign>true</PublicSign>
   </PropertyGroup>
 
+  <ItemGroup Condition="'$(TargetFramework)' == 'net48'">
+    <PackageReference Include="PolySharp" PrivateAssets="all" />
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="FluentAssertions" />
   </ItemGroup>
diff --git a/src/PAModelTests/RoundtripTests.cs b/src/PAModelTests/RoundtripTests.cs
index 066580a0..f4c42eb5 100644
--- a/src/PAModelTests/RoundtripTests.cs
+++ b/src/PAModelTests/RoundtripTests.cs
@@ -18,7 +18,7 @@ private static IEnumerable<object[]> TestAppFilePaths
             var appsDirectory = new DirectoryInfo("Apps");
             foreach (var file in appsDirectory.EnumerateFiles("*.msapp", SearchOption.AllDirectories))
             {
-                var testAppRelativePath = file.FullName.Substring(Environment.CurrentDirectory.Length + 1);
+                var testAppRelativePath = file.FullName[(Environment.CurrentDirectory.Length + 1)..];
 
                 yield return new object[] { testAppRelativePath };
             }
diff --git a/src/PAModelTests/YamlTest.cs b/src/PAModelTests/YamlTest.cs
index 80dba430..f4ffb99f 100644
--- a/src/PAModelTests/YamlTest.cs
+++ b/src/PAModelTests/YamlTest.cs
@@ -639,7 +639,7 @@ private static string ParseSinglePropertyViaYamlDotNot(string text)
         // Strip the '=' that we add.
         if (val[0] == '=')
         {
-            val = val.Substring(1);
+            val = val[1..];
         }
         return val;
     }
diff --git a/src/PASopa/.editorconfig b/src/PASopa/.editorconfig
deleted file mode 100644
index 258b6cae..00000000
--- a/src/PASopa/.editorconfig
+++ /dev/null
@@ -1,8 +0,0 @@
-[*.cs]
-
-# Category overries:
-# Disabling these categories because the original implementation didn't have them on and we're not making changes to it at this time.
-dotnet_analyzer_diagnostic.category-Globalization.severity    = silent
-dotnet_analyzer_diagnostic.category-Performance.severity      = silent
-
-# Rule overrides:
diff --git a/src/Persistence/TfmExtensions/MemoryTfmExtensions.cs b/src/Persistence/TfmExtensions/MemoryTfmExtensions.cs
new file mode 100644
index 00000000..a076c74a
--- /dev/null
+++ b/src/Persistence/TfmExtensions/MemoryTfmExtensions.cs
@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+#nullable enable
+
+namespace Microsoft.PowerPlatform.PowerApps.Persistence.TfmExtensions;
+
+public static class MemoryTfmExtensions
+{
+#if !NET9_0_OR_GREATER
+    public static bool ContainsAny(this ReadOnlySpan<char> span, string values)
+    {
+        return span.ContainsAny(values.AsSpan());
+    }
+
+    public static bool ContainsAny(this ReadOnlySpan<char> span, ReadOnlySpan<char> values)
+    {
+        return span.IndexOfAny(values) >= 0;
+    }
+#endif
+}
diff --git a/src/Persistence/TfmExtensions/StringTfmExtensions.cs b/src/Persistence/TfmExtensions/StringTfmExtensions.cs
index b0770fd9..4894316b 100644
--- a/src/Persistence/TfmExtensions/StringTfmExtensions.cs
+++ b/src/Persistence/TfmExtensions/StringTfmExtensions.cs
@@ -10,6 +10,11 @@ namespace Microsoft.PowerPlatform.PowerApps.Persistence.TfmExtensions;
 public static class StringTfmExtensions
 {
 #if NETFRAMEWORK
+    public static bool Contains(this string source, char value)
+    {
+        return source.Contains(value.ToString());
+    }
+
     public static string Replace(this string source, string oldValue, string? newValue, StringComparison comparisonType)
     {
         // For now, looks like NetFx only supports the Ordinal comparison for Replace
@@ -26,6 +31,11 @@ public static bool EndsWith(this string source, char value)
     {
         return source.Length > 0 && source[^1] == value;
     }
+
+    public static string[] Split(this string source, string? separator, StringSplitOptions options = StringSplitOptions.None)
+    {
+        return source.Split([separator], options);
+    }
 #endif
 
 #if !NET6_0_OR_GREATER