You're the best. Thank you.
fyi I had this idea but didn't try because it says "Custom Category", I thought you can only choose one. Works perfectly now.
Hm... to be honest I never really thought about implementing a function like this purely because the post diffs themselves don't take up a large portion of the database (unless, of course, someone's making thousands of edits to a single post )
Could be part of a "cleanup" admin page, but honestly it's not really that urgent to leave it around, no?
Are you on Redis or Mongo? There is likely a command you can just run to clean it all up.