I've thought about this a couple of times (to myself), but then the way to fix it is just to edit your post and add what ever you want to add underneath

I also don't use multi quote

I'll quote one of the messages, and then either put at the bottom at such and such a user, (post what I want), or start a new reply

plus I've been known to make multiposts in 1 thread at a time, threads like the coping with emotions thread, " tell us about your bad times", just because I think each individual story deserves it's own post

no issue with that

just out of curiosity, what is multiquote and how does it work