Had some more time to sit on this. I think a simple (ish) implementation is maybe on the album view where the album image currently lives theres just an option to swipe through any arts embedded to files on that album. Similar to the way genius lyrics has alternate annotated covers for albums.
Bonus points if you could also display embeded info like cover descriptions. That might be tough though.
I don’t think the ability to view alternate album arts per track is necessary nor would that be great on sync times
I’ve been wanting this too — multiple pictures for back cover, liner notes, gatefolds, booklets. I listen on a tablet, and it would be nice to have that right in front of me. I know this is probably too difficult, but sometimes there is a pdf booklet too.