They're the same port; if they weren't, there'd have been no data on the pads for me to watch...

I presume the same current limitation applies; it can be disabled with a kernel tweak, provided the backpack also has a battery and power-injector; or just use a powered hub, get more ports and no kernel tweak needed.

Yes, we can make peripheral battery-packs with a power injector or powered hub, a fat-max battery, wired ethernet adapter, USB-RS232, and even SIS-based USB-VGA.

(Or, you could leave some of that out, but I would include everything except maybe the USB-VGA. With switches to disconnect everything, there's no power drain unless you use it...)