"Mini eGo" is a very general category! There are several different manufacturers, they come in several mah ratings (300, 350, 380, 400, 450), different lengths, and regulated and unregulated. The unregulated obviously wouldn't be PWM. The regulated voltage ones may or may not be PWM. Boosting the voltage of a 350 mAh battery would, among other things, drastically shorten the charge life and the battery life.
They are cute and useful, but not Power Houses.