Hello bambrose, a Fader per track is already doable and one of the simplest thing to achieve, but as you say this opens a whole new and infinite universe of possibilities.
Regarding being battery powered, the problem is that some controllers will drawn more power than others, using the HUB you quicly will run in to issues so a stable 5V supply is a must.
I see it in a different way, last gig I had this weekend in Austria, the CerebelUSB saved my life, it served my as a phone charger!!
hahaha.
A few weeks ago in France the stage was very “Dark” in light, so I used an USB LED lamp that I bought for 2€, all this in the USB Hub… So I see CerebelUSB as a neat way to save up a lot in cables for Live use…
For small devices, I´m sure you can get a 5V battery and hook it with a Micro USB connection to it…
Cheers!