if your pass
through is hooked up to your PC, go ahead, the current capacity of the USB port is already limiting the atty, meaning, the 5v you think you have, is really a tad over 3.7, because the USB port cannot handle it.
In order to get 5v from a 5v pass
through, you need to use a power supply, such as a 5v, 2 amp wall transformer.
i have used lower resistance atomizers/cartomizers on my variable voltage box up to 5.5 volts, and yes, you run the risk of damaging the atty if you let it run dry OR take too long of a drag.