The current system is just flawed.
As a stopgap i think a good idea would be bumping up the cost of 1st plane spawn by 200 points and reducing the 2nd plane spawn by the same amount. This way both will cost approximately 700-900ish SP.
Tbh i never found 2nd plane spawn too problematic, and ever since it got harder to spawn i had terrible time trying to spade AAs, since there is just so much less planes, especially late game to kill.
The whole thing is much more complicated though since planes’ effectivness greatly varies depending on BR.
At BR 1.0 - 2.0 CAS is very weak and can be effectively engaged by pretty much anything.
At BR 2.3 - 4.0 it gets much stronger, but there aren’t many good fighter-bombers, most of viable CAS at this BR are dedicated strike aircraft which fly like bricks.
At 4.3 - 7.3 we probably get the peak of early CAS. It still takes considerably more effort and is considerably weaker than modern stuff, but you get planes like F4U-4B or Yak-9s that can both carry a decent amount of ordinance while avoiding being free kills for anyone who decides to spawn a fighter.
At 7.7 - 9.7 CAS is much, much weaker. With the introduction of radar AAs and proxy fuse rounds majority of CAS just ends up as food for M249s, PGZs, Wz 305s, Gepards and alike.
And above more or less this BR we get to the truly modern stuff which honestly i think just doesn’t fit the game.
At this point with how large the distances are there is not much skill involved. It will always be one thing countering another.
The maps and modes just don’t support such incredibly powerful weapons which constantly with every new update end up breaking the game in some way. Even if gaijin follows up with fixes, it’s like putting a bandaid on a severed limb.