Hi there,
great to see someone working on the Linux drivers! Did I understand it correctly, that this keyboard gets unresponsive on a vanilla Linux install, as soon as you press a special / macro key?
Also, for the Linux support, have you taken a look at hidraw (kernel module)? It passes raw HID events directly to userspace - they don't get processed in contrast to hiddev. You wouldn't need to de-attach the keyboard from the hid-generic kernel module, so general stuff can still be done using it. You can talk to the keyboard via HID feature requests.
Keep up the great work!
Cheers,
Tolga