Given this tip, this comment and possibly others, it would be nice if git-annex could look at any given repo and make suggestions for improvements. As a second step, it could look at remotes as well. And as a third, maybe even change repo settings and not just make suggestions.
Having a few old repos with terabytes of data on various disks, I would just toss this stanza into my mr templates to eventually optimize all my repos to current best practices.
-- Richard
One of those was fixed by improvements to git-annex, the other is not something that a command like the mooted one would be able to safely do since it has to happen at repository init time.