[YouTube] Duplicated Menu Button

[cyfung1031]

If the experimental flags "kevlar_tuner_should_test_maintain_stable_list" and "kevlar_should_maintain_stable_list" are enabled, the settings button will be added every time after clicking the "3 dots."

UserScript to enable both flags for testing.

// ==UserScript==
// @name        Testing Script 186
// @namespace   Violentmonkey Scripts
// @match       https://www.youtube.com/live_chat*
// @grant       none
// @version     1.0
// @author      -
// @description 8/19/2023, 11:41:39 PM
// @run-at              document-start
// @grant               none
// @unwrap
// @allFrames           true
// @inject-into         page
// ==/UserScript==

(() => {
  'use strict';

  const updateFlags = () => {
    const EXPERIMENT_FLAGS = (window.ytcfg && window.ytcfg.data_) ? window.ytcfg.data_.EXPERIMENT_FLAGS : null;
    if (!EXPERIMENT_FLAGS) return;
    Object.assign(EXPERIMENT_FLAGS, {
      kevlar_tuner_should_test_maintain_stable_list: true,
      kevlar_should_maintain_stable_list: true
    });
  };

  const mo = new MutationObserver(updateFlags);
  mo.observe(document, { subtree: true, childList: true });

  updateFlags();

})();

Screenshot: