Could be like the 1000 lb bomb option on the P-51. We've only found one instance where they were used (Iwo close support missions) but we have it in game, all the time.
That's a different thread (also splitting up rockets, or bombs. but not both). Albeit one that I'd support
FLS.... The F6F could take 20mm cannons. The P-40 was built with the ability (from the factory design) to carry 20mm cannons also. There are a large number of weaponry loadouts that are pure fantasy (that is, they never, or in only 1 rare case ever used these loadouts in the real war).
Do we want to have such fantastical setups? Most of us do not. This is a WW2 game and the vast majority of us play it to immerse ourselves into WW2. Not to just make things up (i.e. Luft '46 style) because they were a plan, or they were written on paper somewhere but never built/realized/used in the war.
We already have precedent for what should and should not be in the game. We have the removal of the 109F gondalas, the rolling back of the 109G6 to be late-1942 era (no 30mm), the removal of wing gondolas on the 109K4... and all these examples are just on one single family of craft! There are more!
The overload option was rarely if ever used by a single group for limited use in ground strafing. It's highly unrealistic to have them going around spraying 3600 rounds of ammo per plane -- yes I'm guilty of this too -- when it only carried about 300 per gun.
You want to talk about what COULD be done vs what WAS done? That's another debate, feel free to start a new topic.