He's not trying to complete on price w/ Microsoft; So there's nothing stopping him from buying an official controller for each one he builds to get the interface hardware. It just becomes part of the BOM cost.
Then he just has to replace the buttons and joysticks with ones that work for his end-users.
As one of the people that would MUCH prefer this style of practice:
Is there a good way to find Doctors that practice EBM, or will I have to call around and ask each one what their take is?
The issue is not that people can/can't stop at two beers. It's that they could have stopped at one beer, waited 75 minutes for it to metabolize fully, then drive home. At that point the device could still say they are over the limit, due to a programming bug. We don't know how well it was implemented, what the failure conditions are, how it handles those failure conditions, etc.
So the issue is: Would you like to be convicted of a crime you didn't commit, all because some people can't stop at two beers?
Ya'll hear about the geometer who went to the beach to catch some rays and became a tangent ?