ENGAGED - spring loaded in, both pilots have pitch control DISENGAGED - pulled out and turned 90° clockwise or counterclockwise, the pilot with the free control column will have pitch control
ENGAGED - spring loaded in, both pilots have roll control DISENGAGED - pulled out and turned 90° clockwise or counterclockwise, the pilot with the unjammed wheel will have roll control
Depending on which position you pick as your role in the Q4XP will determing which yoke you are implied to be holding, and as such which control surface you will move with your yoke when you disconnect the two sides.