Hi,
I use an ultimate hacking keyboard with a trackball module. https://ultimatehackingkeyboard.com/
Now, on my client the keyboard works. But, my trackball doesn't. I opened an issue with the firmware team. UltimateHackingKeyboard/firmware#760
What they are saying is USB HID report parser, we might have to fix. I can help if we can get this fixed.
Regards
Mo