diff --git a/scripts/format-scope.json b/scripts/format-scope.json
index ea5240d82..16dbe251a 100644
--- a/scripts/format-scope.json
+++ b/scripts/format-scope.json
@@ -156,5 +156,6 @@
   "scripts/qa-map-source-controls.mjs",
   "src/ui/layers.js",
   "src/ui/layerPanel.js",
-  "src/ui/clearLayersControl.js"
+  "src/ui/clearLayersControl.js",
+  "scripts/qa-layer-panel.mjs"
 ]
diff --git a/scripts/qa-layer-panel.mjs b/scripts/qa-layer-panel.mjs
new file mode 100644
index 000000000..ef458bee7
--- /dev/null
+++ b/scripts/qa-layer-panel.mjs
@@ -0,0 +1,115 @@
+#!/usr/bin/env node
+/** Browser proof of Layers panel replacement and subscription ownership. */
+import puppeteer from 'puppeteer';
+const browser = await puppeteer.launch({
+  headless: true,
+  args: [
+    '--no-sandbox',
+    ...(process.platform === 'darwin'
+      ? ['--use-angle=metal', '--enable-gpu']
+      : ['--use-gl=angle', '--use-angle=swiftshader']),
+  ],
+});
+const page = await browser.newPage();
+let failures = 0;
+const errors = [];
+page.on('pageerror', (error) => errors.push(error.message));
+const check = (name, passed) => {
+  console.log(`[${passed ? 'PASS' : 'FAIL'}] ${name}`);
+  if (!passed) failures++;
+};
+try {
+  await page.goto(
+    `${process.env.QA_BASE_URL || 'http://localhost:4173'}/?welcome=0`,
+    { waitUntil: 'domcontentloaded' },
+  );
+  await page.waitForFunction(
+    () => window.__godsEyeView?.dataManager?._layerPanel,
+    { timeout: 60000 },
+  );
+  const results = await page.evaluate(async () => {
+    const manager = window.__godsEyeView.dataManager;
+    const container = manager._toggleContainer;
+    const id = 'qa-panel-lifecycle';
+    let listener = null;
+    let enabled = 0;
+    window.__gevQaRegisterLayer(manager, {
+      id,
+      name: '<b>Literal layer</b>',
+      icon: '◌',
+      source: 'Local fixture',
+      updateInterval: -1,
+      init() {},
+      enable() {
+        enabled++;
+      },
+      disable() {},
+      update() {},
+      destroy() {},
+      getStats: () => ({ count: 1250, lastUpdate: Date.now(), stale: true }),
+      getRowControls: () => ({ chips: [] }),
+      setRowControlsListener: (callback) => {
+        listener = callback;
+      },
+    });
+    const result = [];
+    try {
+      manager.buildTogglePanel(container);
+      const row = () => container.querySelector(`[data-layer-id="${id}"]`);
+      const first = row().querySelector('.data-toggle-btn');
+      result.push([
+        'descriptor text is literal content',
+        row().querySelector('.data-name').textContent ===
+          '<b>Literal layer</b>' && !row().querySelector('b'),
+      ]);
+      result.push([
+        'count is presented from the supplied snapshot',
+        row().querySelector('.data-count').textContent === '1.3K',
+      ]);
+      result.push([
+        'row subscription is installed',
+        typeof listener === 'function',
+      ]);
+      manager.buildTogglePanel(container);
+      first.click();
+      await Promise.resolve();
+      result.push([
+        'a detached row cannot issue an enable action',
+        enabled === 0 && !manager.isEnabled(id),
+      ]);
+      await manager.setEnabled(id, true);
+      result.push([
+        'feed state reflects the settled layer snapshot',
+        row().querySelector('.data-toggle-btn').dataset.feedState === 'stale',
+      ]);
+      const final = row().querySelector('.data-toggle-btn');
+      manager._layerPanel.destroy();
+      final.click();
+      await Promise.resolve();
+      result.push([
+        'destroyed panel releases row subscriptions',
+        listener === null,
+      ]);
+      result.push([
+        'destroyed controls cannot change the layer',
+        manager.isEnabled(id),
+      ]);
+    } finally {
+      manager._layerPanel?.destroy();
+      manager._layerPanel = null;
+      await window.__gevQaUnregisterLayer(manager, id);
+      manager.buildTogglePanel(container);
+    }
+    result.push([
+      'ordinary layer rows return after reassembly',
+      container.querySelectorAll('.data-toggle-row').length > 10,
+    ]);
+    return result;
+  });
+  for (const [name, passed] of results) check(name, passed);
+  check('no uncaught browser errors', errors.length === 0);
+} finally {
+  await browser.close();
+}
+console.log(`RESULT: ${failures} failures`);
+process.exitCode = failures ? 1 : 0;