big performance gains by deleting .concat and adding in .push and .flat!

inject.js

@@ -365,17 +365,17 @@ function getShadow(parent) {
     if (parent.firstElementChild) {
       var child = parent.firstElementChild;
       do {
-        result = result.concat(child);
+        result.push(child);
         getChild(child);
         if (child.shadowRoot) {
-          result = result.concat(getShadow(child.shadowRoot));
+          result.push(getShadow(child.shadowRoot));
         }
         child = child.nextElementSibling;
       } while (child);
     }
   }
   getChild(parent);
-  return result;
+  return result.flat(Infinity);
 }
 function getController(id) {
   return getShadow(document.body).filter(x => {