Grouped BGM Problem. Help in developing plugin.

[Warilized]

Regarding this request post of mine. I actually developed my own plugin with this idea, yay~ lol.
A bunch of thanks for Caethyril for helping me.

It works alright
It will play BGM of the referenced map, even if the current has no BGM. If the current map has BGM it will get played instead.

A bit of problem though, this plugin invalidates BGM change through auto run event (unless if "wait: ~10 frames" are added before changing). It can still do it with other trigger though.
It only invalidates the auto run event at the same time it detect a change in <bgm_reference: [MapID]>.
If the <bgm_reference: [MapID]> is the same as the map before, it will let you change BGM through auto run event like normal.

Do you guys have any idea how to solve it? I have tried what I know.

Spoiler: The plugin code

(function($) {

  var currentGroup;
  
  const BGM_Group_Autoplay = Game_Map.prototype.autoplay;
  Game_Map.prototype.autoplay = function() {
  BGM_Group_Autoplay.call(this);
    var BGMGroup = parseInt($dataMap.meta.bgm_reference);
    var mapRef = 'Map%1.json'.format(BGMGroup.padZero(3));
    loadReference = function(src) {
      var xhr = new XMLHttpRequest();
      var url = 'data/' + src;
      xhr.open('GET', url);
      xhr.overrideMimeType('application/json');
      xhr.onload = function() {
        if (xhr.status < 400) {
          dataMapRef = JSON.parse(xhr.responseText);
          DataManager.extractMetadata(dataMapRef);
          if (BGMGroup != currentGroup) {
            currentGroup = BGMGroup;
            AudioManager.playBgm(dataMapRef.bgm);  
          }
        }
      };
      xhr.onerror = ResourceHandler.createLoader(url, loadReference.bind($, src));
      dataMapRef = null;
      xhr.send();
    };
    if (BGMGroup > 0 && !$dataMap.autoplayBgm)  {
      if ($gamePlayer.isInVehicle()) {
          $gameSystem.saveWalkingBgm2();
      } else {
          loadReference(mapRef);
      }    
    }
  };

})(eqD.groupedBGM);