It uses a 5 port since it's a double acting air cylinder otherwise it wouldn't retract and the cylinder rod would rub on top of the drawbar.
You could use a 3 port solenoid if you use a single acting cylinder with spring return, that's what I used on the first pdb on the x2.
The bellevilles have no control over retracting the cam/rod off of the drawbar to create clearance to prevent rubbing.
Hoss