diff --git a/installer/common/SampleInstaller.nsh b/installer/common/SampleInstaller.nsh
index 505802d..bb6a47a 100644
--- a/installer/common/SampleInstaller.nsh
+++ b/installer/common/SampleInstaller.nsh
@@ -180,6 +180,11 @@ Section "${SAMPLE_DISPLAY_NAME}" SecApp
     FileWrite $0 '  "icon": "icon_${SAMPLE_SLUG}.png",$\r$\n'
     FileWrite $0 '  "icon_3d": "icon_sbs_${SAMPLE_SLUG}.png",$\r$\n'
     FileWrite $0 '  "icon_3d_layout": "sbs-lr",$\r$\n'
+    ; Unity/engine apps gate their render on the main window being SHOWN, so the
+    ; shell must launch them SW_SHOWMINNOACTIVE (not SW_HIDE) and they read
+    ; xrGetWorkspaceTileSizeDXR for tile size. Opt-in flag consumed by the shell's
+    ; per-app show mode (displayxr-shell-pvt#80). All Unity samples are engine-gated.
+    FileWrite $0 '  "engine_render_gated": true,$\r$\n'
     ${WordReplace} "$INSTDIR" "\" "/" "+" $1
     FileWrite $0 '  "exe_path": "$1/${APP_EXE}"$\r$\n'
     FileWrite $0 '}$\r$\n'
diff --git a/samples/desktop-avatar/Assets/DemoWindowController.cs b/samples/desktop-avatar/Assets/DemoWindowController.cs
index 9a47fe7..e418111 100644
--- a/samples/desktop-avatar/Assets/DemoWindowController.cs
+++ b/samples/desktop-avatar/Assets/DemoWindowController.cs
@@ -104,6 +104,14 @@ void Update()
 #if UNITY_STANDALONE_WIN
         if (Application.isEditor) return;
 
+        // Workspace-tile mode (#225): the shell/runtime owns the window — it
+        // syncs the hidden window to the tile's 3D-window pixel rect so Kooima
+        // (from the tile pose) matches the render aspect (this is what every
+        // other tile app gets for free). Restoring/persisting our own portrait
+        // size here overrides that cell-resize and mismatches Kooima → the whole
+        // scene stretches. So this window-chrome policy is inert as a tile.
+        if (DisplayXRNative.displayxr_is_shell_mode() != 0) return;
+
         // Remember / restore window size AND position across launches (the split
         // persists separately in TigerSpeechBubble). On the first valid frame,
         // restore the last-saved size + position; thereafter, track changes in