+1. Its always been a mess once you have more than a couple of pages. Now with 5.7 its far worse, especially where you hold licenses for the same addon in legacy and 5.7. What you suggest is a minimum. Look at the number of questions about licenses that come up on the forums. Its an indication the whole way licenses are managed needs re-thinking.

It would also be useful to have a marker on theme/addon pages when you search the marketplace to let you know how what licenses you hold and where they are assigned. But that kind of usability enhancement is probably asking too much.