Synergy/Barrier support

I know this might get me thrown from the high tower, but I would like to use Barrier (2.3.3) with Qubes (4.1).

I am aware of the general security implications. (Not going to type passwords this way, only used for text editing. Still better than sending files back and forth I guess…)

I installed Barrier and I am running it in sys-usb with the firewall enabled.
Unfortunately neither running it in sys-usb nor running it in its own VM yielded any success. Barrier is not registering as an usb device but uses some form of IPC instead which gets eaten somewhere along the way I guess.

Does anybody know how this should/could be solved and how keyboards and touchpads on laptops are handled in general?

I think both Synergy/Barrier and my laptop’s keyboard and touchpad use PS/2 and CPU interrupts. Is that possible?