HMm... okay that does actually save me a button click or (if not a slot). Shift+4 can always be turn em 'on and Shift+5 can always been turn 'em off!
Neato!
The other use case I had was, if I'm jamming my fast recharge melee attack (like Barb Swipe) and it's on CD, I *may as well* Brawl someone. But that sounds like a usecase that is explicitly designed to be avoided.