If the community agrees, there should be a cover art type for "fan edited" or "touched up" covers (like what is often used in the Album Art Exchange). I don't want to see such submissions confused with official artwork, but wouldn't mind if there were a way to clearly mark them as unofficial.

If the community doesn't feel that this type of artwork is appropriate for the CAA, then the style guidelines should make this clear.

relevant edit: edit #35669794