I'd find it handy. I think there's some risk in agents tripping over stale tickets and consuming tokens - I see it with .md all the time.

Tickets by dependency would be nice (although my agent hasn't really used dependencies yet), and ideally something to just quickly wipe out closed tickets with a single command would be nice.

Or at least move them to a .tickets-done directory, so if the agent is searching under .tickets it won't see them, but you retain some history.