Using Media3 in AppInventor2

I'm trying to create an extension for AppInventor 2 that uses the Media3 library, with MediaLibraryService . After some minor modifications, I managed to start sessions with a notification with the standard 3 buttons. Now I would like to extend the functionality of the extension by adding custom buttons in the notification. Unfortunately, the library uses RemoteViews and layouts, which are not allowed by AppInventor limitations, we can't add resources to the extension. Is there another custom way to add buttons? Or is there a way I could fork and modify the library for my own use so that the custom buttons don't use the layout? Is it possible?