Hi Barry,
You could store the setup for both Qu-Drive and USB B streaming.
Go to Setup > IO Patch > USB Audio
Assign USB channels 1-30 to CH 1-30 and USB channels 31-32 to L and R
Save this as a scene for USB B
Now go back to the USB Audio patch screen.
Assign USB channels 1-16 to CH 1-16 and 17-18 as L and R
Save this as a scene for Qu-Drive
Now go to the Scenes page and press the filter button next to the two scenes we have just made.
Now block all settings other than Output Patch for both scenes.
I hope this helps!
Thanks,
Alex