Question about the OP MK2 case: were you aiming at the Kitfox, or leading it, effectively aiming at something in the background? Former I would call an issue; latter, expected given the way things work currently.
Thought had occurred to me to fake zeroing weapons convergence by, at the press of the appropriate button, creating an aiming-collision plane client-side in the direction the player is aiming (I assume projectile direction is communicated by client rather than derived by server based on position and aim point, or something), at the current piper distance, or perhaps at the target's distance -- perhaps a separate button. (I suppose the 1500m limit a separate mechanism? Or could that be coerced into the desired behavior?)
Of course, the weapon(s) would still converge nearer when aiming at something in the foreground. But I don't imagine that would create problems for people.