I’d like to preface this by saying that I fly CAP most of the time (as in, using planes as SPAA), but also do CAS regularly in small amounts if there’s nobody for me to shoot down. These suggestions are also mostly relevant for mid tier.
Reduce spawn cost of the actual plane, severely increase spawn cost of any A2G stuff. Especially the very effective stuff like the FAB-5000 and 12000lb bombs.
Using planes as SPAA is the most effective method and this would improve that, as a pure fighter wouldn’t cost almost as much as one loaded with bombs.
Just add more SPAA, the forum is FULL of great suggestions for almost any tree. Especially USA in the 4.0-7.7 gap. I can name quite a few just off the top of my head.
Potentially add some form of ground radar station which would tell SPAA (of any time period) if there is an aircraft up, and direction/altitude. This is more of a general idea, nothing specific.
Increase SPAA rewards. Shooting down aircraft doesn’t pay well due to low activity % (hence little incentive to do so), a possible solution is having SPAA be spawnable from another vehicle (similar to the AT guns from the Sturmtiger event, or the scout drones on high tier light tanks where you can switch between either vehicle at any time). This way, a player wouldn’t have to throw away the tank they’re using to shoot a plane down.
Lower airspawn of all aircraft so they’re easier to intercept and heavy bombers mentioned above aren’t nearly invulnerable to gun SPAA just by virtue of being so high up. Regular attackers would also arrive slower at the battlefield, being easier to shoot down with both SPAA and aircraft.
I don’t want airfield spawns for them because in a marker-less mode like Ground RB, they’re much harder to spot than when they’re contrasting against the bright sky.
Ability for SPAA to resupply all their ammo, anywhere on the map, just once per spawn. Hit a key, and it gets instantly replenished, or a resupply zone spawns on the ground under your vehicle.
At high tier, introduce an artificial ceiling done by longer-ranged SAMs - go above a certain altitude, say 5km, and you get bonked by an S-75 or HAWK, or even the bigger stuff like an S-300. There should be an on-screen warning for this similar to the map border one - this is to deter someone sitting 10km up dropping guided bombs.
Also not entirely sold on this idea, but WW2 spaa would have a sorta aim assist where if you target a plane, it’ll show you a little straight line of the direction it is travelling in. Won’t tell you lead or anything, just its direction.
Also not entirely sold on this, but high tier SPAA could enable its player to spawn a ‘free’ fighter kinda like Arcade, with a longer timer or none at all. This would enable players who haven’t ground out an air tree to also hit aircraft beyond the range of their SPAAs.