The new renderer is causing Flash objects to be instantiated before any nested param nodes have been added, they are read and parsed at creation and never touched again. EDIT: I'm assuming the Flash object is loaded immediately upon insertion into the DOM and not at the next tick.

This only happens on IE AFAIK (all versions including Edge). Related to the performance-special-case in the renderer?

cc @spicyj 

* See https://github.com/spicyj/innerhtml-vs-createelement-vs-clonenode.
 */
var enableLazy = (
  typeof document !== 'undefined' &&
  typeof document.documentMode === 'number'
  ||
  typeof navigator !== 'undefined' &&
  typeof navigator.userAgent === 'string' &&
  /\bEdge\/\d/.test(navigator.userAgent)
);
function insertTreeChildren(tree) {
  if (!enableLazy) {
    return;
  }
  var node = tree.node;
  var children = tree.children;
  if (children.length) {
    for (var i = 0; i < children.length; i++) {
      insertTreeBefore(node, children[i], null);
    }
  } else if (tree.html != null) {
    node.innerHTML = tree.html;
  } else if (tree.text != null) {
    setTextContent(node, tree.text);
  }
}
var insertTreeBefore = createMicrosoftUnsafeLocalFunction(
  function(parentNode, tree, referenceNode) {