Extra fields from MusicBrainz (missing fields)

Yanno, for all that beets prides itself in being the tagger for OCD music lovers, i'm a little surprised at the info it doesn't pull from musicbrainz.

It doesn't pull performer, composer, lyricist, conductor, engineer or producer tags. In short, why not just pull ALL the tags that it can from musicbrainz (see here https://picard.musicbrainz.org/docs/mappings/ ) and apply it to the file and database for searching. Why wouldn't i want to find all the various tracks that Jon Coltrane plays on even when the album title or group doesn't bare his name?

I'm just learning Python now, so should i take a shot at this? Should it be a plugin, or should i not bother because it's on the roadmap?

Start by reading the MusicBrainz Picard mappings linked in the issue and reviewing how beets currently imports MusicBrainz data. Define which additional fields should be supported, how they should be applied to files and the database, and how they become searchable; the issue names no files or tests to run.

Written by the indexing model from the issue text.