Yeah, there has been discussion on the matter for sure.
As far as I can recollect right now it is about being able to preserve artwork when you have selected 'clear existing tags' and added 'artwork' to the exceptions list of tags (metadata) not to be cleared.
Until now you can't make an exception for artwork.
What I do myself: I have two separate portable Picard installs.
(well, actually six, but I should discuss that with my shrink)
The first one clears all tags, with only the most essential ones such as Album Artist, Artist, Title, and the MusicBrainz release ID in the 'exceptions' list.
Those get written afresh.
So that results in files that are spanking clean.
Then I run them through a full-fledged Picard with all bells and whistles. (scripts and plugins)
So Picard #1 has 'clear all tags', Picard #2 doesn't.
I won't lie that it was some work to set it all up, but it is saving me an enormous amount of time now that I have it working.
It now takes me only a couple of mouse clicks and perhaps some 30 seconds to go from garbage metadata to perfection for an album.