Thanks again for taking the mantle on this, Dave!
I have a bit of spare time now to test stuff as I also have detailed tagging for classical music.
However, I'd like to come forward with a request of my own as well, which would entail a change in KODI.
I come from foobar2000 which so far has been the gold standard of tagging for me. I have tagged some albums with musicbrainz, but not all.
foobar2000 uses the semi-colon ';' as delimiter for fields that accept multiple values.
My problem in KODI:
The advancedsetting-parameters <itemseparator> and <artistseparators> seem to be partly reduntant and conflicting.
KODI recognizes the foobar2000 delimiter as a comma ','. Consequently, I have defined
<itemseparator>, </itemseparator> <!-- separator used for multiple artists/genres in tags. Note, this is *comma* *space* -->
This works fine for genres, which are appropriately split. I doesn't work that well for artists called "Earth, Wind & Fire" or "Crosby, Stills, Nash & Young". In the first example, KODI creates two artists, in the second example three artists. All of them have the complete discography for the correct group assigend, though.
This doesn't change if the musicbrainz ID are present, as <itemseparator> seems to take priority.
Now, my proposal would be to exempt artists from being treated through <itemseparator> and be exclusively treated through <artistsseparator>. This current treatment seems to be redundant. The latter filter allows me to define
<separator> and </separator>
<separator> And </separator>
<separator> feat. </separator>
<separator> Feat. </separator>
<separator> with </separator>
<separator> ft. </separator>
<separator> Ft. </separator>
and all should be well (as long as I change all group names that have 'and' to '&', like 'Martha and the Muffins' => 'Martha & the Muffins... no big deal and doesn't hurt scraping).