Many tanks and some healers like to spam queue until they get something in-progress, creating some insanity of a potential party member canceling after canceling after canceling.
There are two easy solutions.
- Two checkboxes, "Join Fresh Group" and "Join in Progress" People that want to dig for in-progress runs can exclusively check this box. Others may exclusively check fresh groups. If you're like me, I'd check both. I do love picking up the last boss of an instance for full myth, but I also like starting with a fresh group.
- Canceling out of a queue puts a 3 or 5 minute DF cooldown on you. Any decent group can do WP in 25 minutes, so, unless you got your in-progress first-whack, you're going to be wasting a lot of time. There are legitimate reasons to cancel, like you got a phone call and don't want the distraction, or a friend asked for help and you'd rather go do that first.