diff --git a/Launcher.Next.Application/LegacyConfigurationProbe.cs b/Launcher.Next.Application/LegacyConfigurationProbe.cs
index 8a71b71..3fa2750 100644
--- a/Launcher.Next.Application/LegacyConfigurationProbe.cs
+++ b/Launcher.Next.Application/LegacyConfigurationProbe.cs
@@ -4,7 +4,7 @@ using Launcher.Next.Core;
 
 namespace Launcher.Next.Application;
 
-public sealed record LegacyConfigurationProbeRequest(ResolvedLegacySettingsPath Settings, ResolvedLegacyDownloadListPath DownloadList, ResolvedLegacyProbeEvidenceRoot EvidenceRoot, string PatternName, LegacyCompatibilityOverlay Overlay, string OperationId);
+public sealed record LegacyConfigurationProbeRequest(ResolvedLegacySettingsPath Settings, ResolvedLegacyDownloadListPath DownloadList, ResolvedLegacyCompatibilityOverlayPath Overlay, ResolvedLegacyProbeEvidenceRoot EvidenceRoot, string PatternName, string OperationId);
 public sealed record LegacyConfigurationProbeResult(string TerminalState, IReadOnlyList<PackageRequirement> Requirements, string EvidencePath, IReadOnlyList<string> Diagnostics);
 
 /// <summary>Read-only configuration inspection. It intentionally has no package,
@@ -15,18 +15,20 @@ public sealed class LegacyConfigurationProbe(LegacyConfigurationAdapter adapter)
     {
         var settingsPath = request.Settings.Value;
         var selectionPath = request.DownloadList.Value;
+        var overlayPath = request.Overlay.Value;
         var evidenceRoot = request.EvidenceRoot.Value;
         if (!File.Exists(settingsPath) || !File.Exists(selectionPath)) throw new InvalidOperationException("LEGACY_PROBE_INPUT_PATH_INVALID");
         if (Path.GetDirectoryName(settingsPath)!.Equals(evidenceRoot, StringComparison.OrdinalIgnoreCase) || Path.GetDirectoryName(selectionPath)!.Equals(evidenceRoot, StringComparison.OrdinalIgnoreCase)) throw new InvalidOperationException("PATH_ROLE_COLLISION");
         Directory.CreateDirectory(evidenceRoot);
-        var before = await Snapshot(settingsPath, selectionPath, cancellationToken);
+        var before = await Snapshot(settingsPath, selectionPath, overlayPath, cancellationToken);
         try
         {
             var settings = adapter.ParseSettings(await File.ReadAllTextAsync(settingsPath, cancellationToken));
             var pattern = settings.Patterns.Where(x => string.Equals(x.Name, request.PatternName, StringComparison.Ordinal)).ToArray();
             if (pattern.Length != 1) throw new InvalidOperationException(pattern.Length == 0 ? "LEGACY_PATTERN_NOT_FOUND" : "LEGACY_PATTERN_AMBIGUOUS");
-            var requirements = adapter.Join(pattern[0], adapter.ParseDownloadList(await File.ReadAllTextAsync(selectionPath, cancellationToken)), request.Overlay);
-            var after = await Snapshot(settingsPath, selectionPath, cancellationToken);
+            var overlay = LegacyCompatibilityOverlayParser.Parse(await File.ReadAllTextAsync(overlayPath, cancellationToken));
+            var requirements = adapter.Join(pattern[0], adapter.ParseDownloadList(await File.ReadAllTextAsync(selectionPath, cancellationToken)), overlay);
+            var after = await Snapshot(settingsPath, selectionPath, overlayPath, cancellationToken);
             if (!before.SequenceEqual(after)) throw new InvalidOperationException("LEGACY_PROBE_SOURCE_CHANGED_DURING_READ");
             var evidence = new { mode="LegacyConfigurationProbe", operationId=request.OperationId, terminalState="LEGACY_CONFIGURATION_VERIFIED", selectedPattern=pattern[0].Name, selectedIdCount=requirements.Count, sourceWrites=false, payloadCopied=false, stagingCreated=false, activationAttempted=false, autoCadLaunchAttempted=false, dfsWriteAttempted=false, inputSnapshots=before.Select(x=>Convert.ToHexString(SHA256.HashData(System.Text.Encoding.UTF8.GetBytes(x)))) };
             var output=Path.Combine(evidenceRoot, request.OperationId + ".json");
@@ -40,6 +42,6 @@ public sealed class LegacyConfigurationProbe(LegacyConfigurationAdapter adapter)
             return new("PILOT_CONFIGURATION_BLOCKED",[],output,[ex.Message]);
         }
     }
-    private static async Task<string[]> Snapshot(string a,string b,CancellationToken ct) => [await One(a,ct),await One(b,ct)];
+    private static async Task<string[]> Snapshot(string a,string b,string c,CancellationToken ct) => [await One(a,ct),await One(b,ct),await One(c,ct)];
     private static async Task<string> One(string path,CancellationToken ct) { var info=new FileInfo(path); return path+"|"+info.Length+"|"+info.LastWriteTimeUtc.Ticks+"|"+Convert.ToHexString(await SHA256.HashDataAsync(File.OpenRead(path),ct)); }
 }
diff --git a/Launcher.Next.Core/LauncherPaths.cs b/Launcher.Next.Core/LauncherPaths.cs
index ef6a144..b478179 100644
--- a/Launcher.Next.Core/LauncherPaths.cs
+++ b/Launcher.Next.Core/LauncherPaths.cs
@@ -29,6 +29,7 @@ public sealed record ResolvedCatalogRoot
 }
 public sealed record ResolvedLegacySettingsPath { internal ResolvedLegacySettingsPath(string value) => Value=value; public string Value { get; } }
 public sealed record ResolvedLegacyDownloadListPath { internal ResolvedLegacyDownloadListPath(string value) => Value=value; public string Value { get; } }
+public sealed record ResolvedLegacyCompatibilityOverlayPath { internal ResolvedLegacyCompatibilityOverlayPath(string value) => Value=value; public string Value { get; } }
 public sealed record ResolvedLegacyProbeEvidenceRoot { internal ResolvedLegacyProbeEvidenceRoot(string value) => Value=value; public string Value { get; } }
 
 public interface IPathResolver
@@ -38,6 +39,7 @@ public interface IPathResolver
     ResolvedCatalogRoot ResolveCatalogRoot(LauncherPathVariables variables);
     ResolvedLegacySettingsPath ResolveLegacySettingsPath(LauncherPathVariables variables);
     ResolvedLegacyDownloadListPath ResolveLegacyDownloadListPath(LauncherPathVariables variables);
+    ResolvedLegacyCompatibilityOverlayPath ResolveLegacyCompatibilityOverlayPath(LauncherPathVariables variables);
     ResolvedLegacyProbeEvidenceRoot ResolveLegacyProbeEvidenceRoot(LauncherPathVariables variables);
 }
 
@@ -100,6 +102,7 @@ public sealed class PathResolver(IReadOnlyDictionary<string, string?>? environme
     }
     public ResolvedLegacySettingsPath ResolveLegacySettingsPath(LauncherPathVariables variables) => new(ResolveExistingFile("LegacySettingsPath", variables));
     public ResolvedLegacyDownloadListPath ResolveLegacyDownloadListPath(LauncherPathVariables variables) => new(ResolveExistingFile("LegacyDownloadListPath", variables));
+    public ResolvedLegacyCompatibilityOverlayPath ResolveLegacyCompatibilityOverlayPath(LauncherPathVariables variables) => new(ResolveExistingFile("LegacyCompatibilityOverlayPath", variables));
     public ResolvedLegacyProbeEvidenceRoot ResolveLegacyProbeEvidenceRoot(LauncherPathVariables variables)
     {
         var value=ResolvePath(Resolve(variables,["LegacyProbeEvidenceRoot"]).Require("LegacyProbeEvidenceRoot"),variables);