Heya,
I've recently thought about this again, and I'd also really wish for tools more flexible when it comes to 'Mixed Tag' handling.
As in, not only that you can choose 1 out of the mixed tags easily as the 'Tag Tuner' example shows (thanks for positing this btw!), but maybe something with which one could also quickly inject, delete and maybe even re-order tags more easily.
And since a picture speaks more than multiple words strung together, and since this thread was a push in the right direction imo already, I did a little mock-up of what would be my ideal 'Mixed Tag Editor' in MusicBee:
So apart from adding & deleting quickly, what I would really wish for is a functionality to also easily add & re-order tags on multiple files with mixed tags as well.
For example in the mock up above, I would love to be able to swap the places of 'Blue Beat' & 'Ska' easily for all files (while keeping the additional unique tags appearing 'later' on some files intact) as well as drag, eg, Mento which is only used on 1 file as is, to the 'Shared' section in let's say 3rd place, to add Mento as a genre value to all files as the 3rd tag value for 'genre' and inject it before the 'unique' tags on each file.
Churs.
c.