Extreme:
I'm not one of those you listed, but since there has been no response so far, here goes

I too am someone who goes for the position and not the shot
per se. In other words, I E-fight. Also, deflection shooting is one of my favorite types of shooting. Here's what I've done to help my gunnery:
1. Offline I set my favorite converge, then while flying level fired off rounds and watched where they placed on my gunsight. Though there was a good portion of straying rounds the majority did converge within a particular area before dropping away. When I found that area I positioned my head so that the groupings were converging in the center of my gunsight. Then I saved it.
2. When pressing the trigger, I try to keep all extraneous stick movements to a minimum. Sometimes it takes longer to lay in that burst, but wasting rounds is so
sloppy IMHO

3. My only ride is the La-5FN so it is difficult to make deflection shots for targets below my gunsight (damn air intake
). However, I do make deflection shots for all other angles. Basically, it's practice makes perfect. I try to set it up so that the target and I will intersect, then anticipate when the target will cross my guns so I can lay in a burst
right before they get there. It's a lot of variables, but for me the key is trying to keep the target in view for that short length of time right before it crosses my guns.