Why would it be a different penalty than the one on when you leave an instance? It's one in the same as if you do leave an instance first, you're inconveniencing the group and leaving them dry. Also, the queue still will give you other people. No, a 30 minute penalty, I think, is enough. Besides, if someone wants to do it, they'll still do it, 12 hour penalty or not. 12 hours is a bit excessive. You pretty much remove that person's ability to do anything in the game which is wrong for something that at most can cause about an hour of problems for a DD.
30 minutes is more than enough![]()