I know this probably has no bearing on quail, but I've helped every single duck I've incubated out of the shell...
Probably not the wisest course of action, but not one of them has died as a result of my helping. I kicked myself when I let 'nature take it's course' and a Silver Appleyard died in the shell after internally pipping.
On the other hand, one duck practically JUMPED from the shell, so I didn't help him.
I have helped both ducks and quail out and they have been fine but you really are taking a risk because if you help them out too soon they will die later on and if you help them out too late, they die as well. Just have to get the timing just right.