The idea is kind of interesting, what I'd like is the ability to set 'bands' like some squads did (or so the internet told me at some point) so you could go from 1 tracer every 5 to 1 every 3 at 25% or however you want it.
How much input did the individual pilots have to the crew chief? Did they get to specify their loadouts? I know I'd sure like to tell him to unmount the MG's on my 109K. I'd also like to be able to tell him to shoehorn in the other 2 20mm's in the front of my 410.
However, for A2A, it would seem to me there would be no advantage to anything other than HE. Also, I assume you're not proposing HE versions of .50 cal and .30 cal because that would be silly.
Doubt it'll happen, but it would be fun.
Wiley.