psychoadept: you might want to try Kid3 (
https://kid3.sourceforge.io/), which will import from MusicBrainz. Highlight the track, then drop File-->Import from MusicBrainz Release, or Import from MusicBrainz Fingerprint, both of which result in a bunch of options and tags.
I have never used Kid3 with MusicBrainz so can't comment further, but I use this app for all my tagging incl. M4A. The developer is very responsive via email.