Okay, I can understand your logic, but let me explain my logic here. While waiting for a DF que, one of the things I do to pass the time is craft. As I work, I get more and more into it. I might even find myself attempting an HQ combine with a bunch of HQ materials. And then right after I start crafting, my DF pops. Now I am in trouble. I can't cancel my crafting or you guys delete all of those valuable materials. I can't withdraw from the DF, because it could have easily been a 30+ minute wait (I waited 85 minutes once). The only other option is to hurry up and rush through the crafting process, so I can switch classes and accept the dungeon prompt. But then I might accidently use a wrong ability at the wrong time and mess myself up.

So while I understand why you did the above, the fact is, I would REALLY appreciate the ability to just cancel my combine without losing my materials, so that I can quickly take that dungeon pop.