That was all well and good, I think, but then a totally unrelated change was made to make most larger-than-a-starship ships (including spirecraft and golems) "immune to gravity". Meaning immune to grav turrets and logistical stations. I've never liked that change One of the points of the grav turrets, I thought, was that the only counter to them was to blow them up.
So, if the lead ship is immune to gravity, the whole exo is effectively immune to gravity. Unintended consequences, eh? On the other hand, grav turrets are really one of those we-all-know-they're-overpowered-but-they're-fun-that-way units, so implicitly making exos the counter to grav-based defenses isn't the end of the world.
As much as I hate to give you ideas...
Just how long would grav turrets last against exo waves they could slow? I would have expected an exo wave that wanted to run past to have focused them down, and since some of them have raid starships along even FFs wouldn't necessarily keep the grav turrets alive. Do AI ships just not go after grav turrets as aggressively as I think they do, or do the escorts not help the lead ship shoot them due to them not being directly effected? If AI ships aren't focusing down grav turrets that are keeping them from getting where they want to go, they probably should be.
If you did revert the grav immunities, sticking in some logic for exo waves with large enough budgets that raid starships become relatively cheap to make sure they include at least a ship or 2 that can shoot through forcefields to be a threat to grav turrets protected that way might be a reasonable tradeoff (assuming the exo waves would actually shoot the grav turrets).