One field that I typically configure with other ID3 editors, is the boolean of whether a track is considered part of a collaboration or not. For example, when an album has tracks with different artists, then this field should be set to true.
If the collaborator field is not properly configured, then iTunes will screw up the albums, either joining many albums into a single massive fake album, or else splitting an album into individual fake albums. That’s why this field is so critical to get right.
I don’t see a way to toggle this metadata entry in the current stable Picard release for macOS. Can we please make sure this field is included alongside the other ID3 fields?