if you can connect to the universes seperately (maybe similar to how xlights connects to the Etherdongle, might be a start) it might be possible, but i think you'd need a seperate plugin for Vixen to talk to the device.
if this might be of some help, in vixen, i can have it run the show via the etherdongle, and while it's running, i caqn still test equipment via the usb dongle.
it might help you in the long run keeping track of everything as well. but that's my 2 cents
someone else might have a way.