From debug testing I can report that the AI often rebases it's Air Def flagged units into border cities at the front. That leaves their core unguarded against strategic bombing. And while the cities themselves can be guarded with anti-air improvements, the tile improvements around them are very difficult to make the AI protect.
Industrial era interceptors have the range of 6, meaning they interception range extend 3 tiles back from the front city. The AI places cities like 4-5 tiles or more from each other. That leaves us with at least a 2 tile radius that will eventually be turned into craters with impunity.
I'm still thinking of a way to make the AI station interceptors in their core. But as long as you have operational range on a unit, the AI will be able to rebase regardless of that air mission command has been assigned in the editor or not. And in order to intercept you need to have operational range. A short operational range of 1 would result in 1 interception radius from rounding up if I'm not mistaken. But even that would result in a 6 rebase range, causing that unit to leave the city.
Another path would be point defense. I've created "Strategic SAMs" that are air units with high Air Defense value and -4HP. They are flagged as "Air Transport" (Air Def results in them performing interception and Air Bombard will result in them bombing) with no carrying capacity and are the target of stealth bombard for ground attack aircrafts/tactical bombers/fighter-bombers, allowing these units to perform SEAD missions against them. Being air units, they can be lethally bombarded.
The Air Transport flag makes the AI rebase them to their front line cities, protecting their offensive aviation there from the player's offensive counter air. If you give them high def value, they could shield other air units from regular air bombard until finally hit and destroyed. The AI still can't use them very intelligently and will often stack more than 4 of them in 1 city. Thus they shouldn't build too many.
Immobile SAM being "rebased" by air in real life.
By not having the "Air Transport" AI strat but another one like "Explore"/"Flag Unit" and being immobile, they will be stuck in their original cities, where they can provide point defense with their AD value. Perfume will make the AI build anything, including things with "Explore" or "Flag Unit" AI strats. So you can have Strat SAMs flagged as "Air Transport" that serve in the front and Strat SAMs that are flagged as "Explore" to serve in the rear.
But what about the tiles? They're still exposed. How can we have the AI position units with AD value on their tiles? What kind of unit would the AI just cover their core tiles with?
"Terraform" AI strat could be the answer. But terraform units only move onto tiles that need working and will move away once the tile has been finished. Still, mobile AA units with zero worker strength could cover bombed tiles while the real workers reconnect them. But then they'll move off and the human would just bomb them again. The AI does not know how to cover its strat res with AA units. Plus the AI would prefer building AA units flagged as "terraform" over real workers despite their worker strength being zero. So they need the king unit treatment or be purely available through auto production.
Or one could have them be immobile and given the Offensive flag and the operational range of 2 with airdrop. The AI would airdrop them and have them stuck there. But from testing the AI would just airdrop them on the same tile instead of covering their territory with them.
With Flintlock patch enabling artillery usage, having AA units flagged as defensive could lead to the AI leaving its cities covered nothing but 2 flak batteries. It's better to have them flagged as "Offensive" and given 0 attack and appropriately perfumed to be built. This way the AI will move them forward with their offensive stack or will defend their cities with them in a pinch but won't treat them as part of the 2 minimum defenders. You could also have some flagged as "Artillery" with bombard range and value to accompany their artillery SOD. AA guns are used to bombard ground targets after all.