I've been experimenting with a new class feature for Monks, looking at their bonus action contention. So far it seems to work mechanically and is fun to use, but I wonder what it has the potential to break or push over reasonable limits? All feedback really welcome.

Refocus
Starting at 5th level, you can push yourself beyond your normal limits for a moment. On your turn, you can take one additional bonus action.
Once you use this feature, you must finish a short or long rest before you can use it again. Starting at 17th level, you can use it twice before a rest, but only once on the same turn.