Not at the moment, those 2 keys are hardcoded in DemulShooter, this was mainly a 'test' setup
I don't know when/if there will be a 'Cxbx' page on the GUI with key selection, etc ...
Untill then, maybe you can try tu remap Q to O with a simple AHK script ?
Depending on how RetroShooter driver is sumulating keypress, it might work