Hi Will,
(am not sure, as I am not in front of my DAW to check).
Isn’t it possible, to re-assign a QuickControl of Halion despite already occupied?
Just try hovering over the desired Halion controller knob, press the right mouse button and assign it to one of the 8 available QC slots?
Am not sure, whether the Halion GUI shows the “modified knob” with its new controller name, or whether just the old one remains.
LG, Juergi