When you are able to track the 88 tracer and use that for adjustment feedback. It's easy to kill bombers at 10,000ft. And if fighters want to furball inside of 3k of the field, it's their fault if they get popped. I regularly kill bombers with the 37mm starting at 4k yards by using the tracers and knowing the lead allowance.
70% of fighter losses in action over the ETO was to light and medium AAA fire when they attacked airfields or ground positions. No different than the price of getting close to fields in the game now.
Why didn't you include CV ack in your wish?