I only use my passthrough off of a modded USB port that runs off a molex connector inside my machine that is running off of a 1200 watt single rail PSU capable of pushing much more amperage than needed. If I pop that then there is a short somewhere or I have a KILLER MOD that would take your head to the clouds. Small smoke machines use about 400 watts.

The powered "professional" hub I linked should power one nicely. The novelty ones are charger only, but I had assumed since the user was asking about room for chargers that they did not need it for a passthrough. Sorry if I confused anyone there.