Hi, I ran into another thing when PreserveMapName is on. I'm using YEP_Message Core that displays the talker's name in a window over the message window. The Window_NameBox is drawn as a child to the main message window. I'm unsure if you already have this paid plugin.
If I talk to an NPC with the name window and open scene_shop, then return to the map with the NPC talking, the name window would remain hidden because it was deactivated when the message was terminated before scene_shop open. I'm using a parallel event. I'm unsure what type of functions would PreserveMapName disable from calling again due switching to a menu from map.
Edit: Currently I have a solution below, but it prevents quick return to the map.
SceneManager.goto = function(sceneClass) {
//preserve map scene before battle and menu
if(this._scene && this._scene instanceof Scene_Map){
if(sceneClass!=Scene_Map && sceneClass!=Scene_Shop){