I guess defenses would need to do something different from what they do now, as packets, bombs, and popdropping is all irrelevant for AR.

I don't think you need to double the efficacy of slots, just add more slots. Starbases are relatively cheap anyway, especially if ISB and AR bonus are stacked.

Another interesting option could be to change the +1 range into +2 for Ultra Stations and +3 for death stars.