How to integrate a stewart platform?


I’ve been building flight sim type rigs for several years now. I’m finally making one large enough for a <300lb person to sit on, presumably while wearing their VR gear.

It would be great for adding immersion to driving and flying games - rally, tank, space, air, maybe others.

It seems to me if Unreal engine had an easy way to export the vehicle motion to a stewart platform then every dev already using UE4 could add support with minimal overhead.
I’m looking for help figuring out how to make my device appear as a USB HID and then receive said motion data. I can build any hardware to support the protocol if someone can explain to me what IS the protocol. I’ve read through these USB HID documents

and I’m still at a loss.

Can you please point me in the right direction? Is there a better place to ask? I also contacted hardware devs for steam VR, and the USB HID group.