Hi again Pete
X-keys have neen out for a while from my understanding, The guy's at viperpit.org who build there own F16 pits use it alot, but then again they are flying BMS, and not fsx in most cases. From talking with them it seemed like the best way to go.
I'm not sure what you mean by this but I'm all ears.
With regards to the computer reading it, it does not fall into the joystick device area but unspecified area as does the track ir as illustrated in the screen.
As for the Pi3 firmware I don't see it and it does not indicated firm ware so I'll check into that one asap and let you know.