Return multiple AlbumInfo/TrackInfo objects for one id

[amogus07]

I recently forked beets-vocadb to be able to obtain metadata from VocaDB, UtaiteDB and TouhouDB at the same time. However, I wasn't entirely happy with the current solution. I wanted to make it possible to disable and reconfigure existing as well as add additional instances (just for fun, ig no one will ever actually want to do that). But after some time, I ran into a problem which I think would have to be addressed within beets.
Logically, the album_for_id and track_for_id methods of VocaDBPlugin should return one match from each of the configured instances, since the latter use the same types of ids, just different corresponding metadata. However, the way beets calls these functions only allows them to return one AlbumInfo/TrackInfo object per id. Would it be possible to change this behaviour to allow one plugin to return a list of objects? Or is there any other way to solve this?