It would be nice to be able to sort music using "artist sort", "album sort", "album artist sort", etc. tags, when defined. It's pretty neat to have artists ordered as <surname, forename> while still being displayed as <forename surname>. I also use them to ignore "the" and equivalents in other languages, and sort artists based on their transliterated name when needed.

Groove Music supports it surprisingly, I think it's the only feature I miss after having switched to foobar.