I think I'm close to my solution, but I don't know how to put the pieces together.
I want to run a mass poster update for my movies, but ignore my fanedits (which are all lumped in to the same movie library). Every fanedit has an edition that contains "fan", and I see that there's a way to use that metadata attribute, as well as a way to ignore locked posters, but I don't see a way to ignore posters that match a given attribute.
If it helps, I also have local poster image files stored with the fanedit video files, so if there's a way I can tell Kometa (or Plex) to ignore the mass poster update in favor of local assets, then that would solve it too.
I don't want to ignore locked posters because that would impact every poster with an overlay from what I understand.
Is it possible to make this happen?