I will be that cat:

It worked in WoW. No tank showing up? Warrior changed from Battlestance to Tank stance and Dutyfinder was restarted. shortened waiting time A LOT.

I would also like to have an option for certain classes to choose if they want to tank or DD. A Warrior can dish out damage mighty fine when defiance is off. With CERTAIN encounters a Monk could tank. Some encounters don't need 2 tanks and shouldn't be enforced in Dutyfinder. Some content doesn't need tanks at all if DDs and healers are good.