"Remind Only" mode for compacting

Auto compact has a habit of triggering at the wrong time, which has resulted in undesirable side effects when I've been refactoring code. Users don't always notice that one is about to trigger. It would be nice if we could have a "remind only" mode for that lets you know when one is due, but doesn't do it until you set it off yourself. At the very least it should wait until after the current operation has finished.