Exhaust width of Valve Body matches it's bore width! No restrictions.
Quarter radius on both the exhaust of the cup seal body and at the inlet to the bolt. This guides the air smoothly up and out. Plus the opeing increase at both turns to make air expand into the larger sapce. Otherwise the air would tumble, like surf, and become turbulant.
Plus the cup seal body has edges raised higher than the cap seat. This is to protect the seat if the valve body is ever taken out of the gun, becasue a small nick will mean a constant leak. Only Alien takes the extra time and effort to give you a better, tougher gun in places like this where most will never see it.