id probably have to look at it. ideally nkey rollover being disabled makes it show up as a hid device
qmk handles composite functions really cleanly too so that’s why it works with qmk. if you verify it works on qmk but not their firmware its gotta be some wacky thing in their firmware about how they’re triggering the events.
there’s even a patch on here to make qmk smart enough to manage nkey rollover even with a a kvm. so you can have nkey you just have to send both the kvm leading keys and hotkeys from the same virtual hid endpoint in key scenarios.