Just buff the damage a little more or reduce damage drop off over distance a little more,
That way some fighters without bombs or rockets can be a little less useless at killing infantry
I’d imagine getting a direct hit from a 20mm cannon very mortal
Not only that… but the velocity should in fact be INCREASED by the plane speed, and thus damage/pen values. Especially if you strafe… the bullets won’t really lose much kinetic force while going towards gravity…
I tried making this arguement in War Thunder and the braindead community laughed at it and said the plane speed is so minor it wouldn’t matter. If the 50mm cannon on a 262 has 85mm of pen at 500m with an initial muzzle velocity of 835m/s, then you should expect a significant increase in pen if you fired the gun moving at 700km/h (195m/s). That extra 195m/s should be applied to the penetration value but it isn’t. 1030m/s is a whole lot faster than the base 835m/s.
Basic physics is too much for the average “netizen” 
There is no problem killing infantry with a/c MG and cannon if you hit them - it is the hitting them that is the issue because htey are usually spread out.
I had a game as Axis Stalingrad last night where I got a dozen or more kills with the Romanian fighter guns - the cap point was at a demolished corner of a building, and shooting the 20mm into that starting from 1000m away was getting me 1-3 kills almost every pass, plus bombing the approach areas as well.
This is actually a really good suggestion because it makes planes with low/no bomb loads less kamikaze-prone. If you can only make one good run with the SBD’s bombs before having to re-supply, you’ll most likely use it as an ATGM and not a plane. But with something like the Bf 110, your autocannons can shred infantry after you’ve used up the rockets, and so staying in the air is worth it.
I’d imagine the option to choose gun convergence would help. Beaufighter and bf 110 already shred infantry with cannons and machine guns and I’d say the weapons being center mounted assists greatly.
Not really sure how the gun convergence is set up on the wing mounted planes in enlisted.
I hope convergence, vertical assist and ammo belts all come over from Warthunder at some point.
One of my favorite things to do in this game is to harass and strafe infantry.
Even after many hours of practice and learning infantry movement from the sky, it definitely doesn’t feel as good as it should, especially when I am getting multiple hit markers when using a supposedly high caliber round from my plane.