Some most excellent news. The phase two application that pipes input received from the Razer Atrox via WinUSB through to a Virtual XB360 Controller provided by VigEm is complete to the point that I was able to fire it up, start Mortal Kombat 11 and play around in the Practise mode.
The test was a resounding success, all buttons worked perfectly (including menu, view and guide) and there was no noticeable input lag as far as my casual eyes and fingers could tell.
At some point I want to write a basic application that will register the exact time (down to as small a unit as possible) that an input even from the virtual controller is received which can paired with similar functionality in the feeder application to collect a good amount of data on the extent to which there is input lag. For now, though, initial signs are good.
I'm going to test the feeder a little more this week and put together a YouTube video demoing it in action as well. Assuming all goes well I will then begin looking for testers along with folks to supply USB packet data from additional devices.
I'll also need to think about next steps with regards to the application. It would be useful, in the long run, to support multiple controllers (this is apparently possible with WinUSB...apparently) and maybe also a GUI and possibly even some install tools to get users up and running nice and quickly.
For now though....time to test