That's a good initiative!
It might be that the USB connection of the Tiny X8 can't be used directly as joystick (might be for USB update only).
Even if it would theoretically be possible to use it as a joystick my guess is it will not be a plug-and-play solution.
If I'm not mistaken the Tiny X8 is Frsky compatible. Then it might be possible to use it with a wireless Frsky receiver such as the Frsky XSR-sim USB dongle or similar. I haven't tried it myself though, so I can only recommend it if you are interested in going down the DIY hacking route.
(Might be easier to just get a Frsky Q X7.... )