I agree. It would be great to be able to have near misses with rockets on an ack cause the gunners to pause at least for a few seconds, or affect their accuracy in some way.
Perhaps what would be better is to create more AAA on the ground by airbases, while decreasing their accuracy and range. By adding a few .50 cal gun positions around a base, decreasing the 30mm accuracy woulndn't upset the balance of field capture by too much.
It seems that all there is for AAA is laser accurate 30mm. I can't even imagine a BOFORS gunner being able to track targets at high speed and deflection angles with even a remote amount of accuracy beyond 1-2k.
Even if these changes cause field captures to be done by many more Jabo than Buff missions, great! It would still require people to cooperate to take a field, and would help mix up the type of aircraft people fly. Buffs are still powerful tools to use for base capture, but they are best suited for strategic attacks.