As long as the coil isn't getting dry (you'll taste it if it does) you're just fine. Your draw is basically going to be a personal thing. Even in more standard cartos and clearos the coils won't pop unless they're burned for quite a while dry, and in some of the larger thicknesses I've had a very hard time popping them.
Edit: To answer one of your questions, my draws on my device are less than 3 seconds because any more and I will be hacking up a lung.