I've thought about this a fair bit. Nothing can prevent you from plainly stating what your device does. You can claim interoperability with USB if your device w

I've thought about this a fair bit. Nothing can prevent you from plainly stating what your device does. You can claim interoperability with USB if your device works for the advertised use. You don't need to pay the USB consortium for licensing, but you can't use their branding. If you don't make a claim about power draw, then I suspect your consumers can't complain unless the power draw is unexpectedly large. And even then, what are the actual damages you need to compensate them for?