That is unfortunate because so many of us image with laptops which have 2-3 USB ports available. The filterwheel gets its own power from a DC connector. The USB bus is presumably needed only to communicate with the laptop and, for a filterwheel, is the rate at which commands/reports are sent back and forth likely to overwhelm the bus like a camera might? With the almost zero knowledge I have of USB specs, I can't even speculate how the hub might have an effect. I'll try connecting directly to a USB port and see if that makes a difference.
Ajay