Ack is useless now. Don't bother manning it.
Planes can fly right down your gunsight and get you every time before you get them. 37mm flak lose the duel every time whether you pump a steady stream of shells right at the attacker, in a cone around its path of flight, or leading it.
How about adding some flak, either increased lethality or new ack choices, that at least has an equal chance the way it used to be?