If I'm queuing for a random dungeon as a healer and the tank is not pulling at minimum 2 packs, I will absolutely pull for them. Healer gameplay is just too boring if there's barely any enemies since we no longer have a lot of damaging abilities. Not only that, if I enable a single-pulling tank then they'll move on to waste someone else's time and turn somebody else's 10-15 minute dungeon into a 30 or 40 minute run.

Usually there's no problem with pulling ahead since the only thing a tank needs to do to pick up aggro is press their aoe skill. That's literally it. On the few times that I've encountered tanks who freak out at me for speeding things along or decide that they're going to let people die by refusing to take aggro, I leave without a word. Because that kind of behaviour demonstrates a kind of ego that needs a reality check.

If you want to go slow, use trusts.