The point and problem as i see it, is the fact the bullets come FROM the center of the cross hair regardless of *forward* head position, aces high has never simulated a true cockpit.
You might want to try that before you stat it as fact.
The bullets come from the correct gun positions and converge with correct lob to be central to the sight at the given range.
simple test, up a Hurri 2 with the 12 guns. set convergence to 600, pull up behind a smaller fighter like a yak/i16. Center your cross hairs on his lower tail at 50ft and fire... your bullets will just stream under his wings and not touch him. If they did in-fact generate from one point then snap shots for 12 BBs would always be at convergence. But that is not the case.