Would be interesting, especially to replace the Defensive Fire that abounds at T8+.
Essentially, at least how I view it, the planes would launch automatically at the start of the battle, and would be, for the USN, 2 squads of two fighters (cannot be given commands, automatically follow an escort order for your carrier), and, for the IJN, two squads of one fighter. They replenish automatically when destroyed or out of ammunition. These would only be available in the Strike or Balanced configuration. Squads engage in a one-to-one ratio (one enemy, one CAP), and prioritize strike aircraft over fighters. They would deplete fighter reserves when available. To pay for this, well, the USN Strike doesn't have fighters, but it would gain a small amount of fighter reserves to supply the CAP aircraft, but the IJN would see their fighter reserves diminished as their CAP aircraft were destroyed.
In addition, CAP aircraft have lower survivability but higher DPS than catapult fighters.