So how are you supposed to actually use that? I don't think there are any computers out there which can provide 100W out of their USB ports.
Am I supposed to unplug the iron from its power supply, plug it into a computer, change the temperature, unplug it, plug the power supply back in, wait for it to heat up, and finally continue soldering? That's awkward enough that even a crappy proprietary smartphone app would've been better!