Nope - no cheats used. Should note that in the save -> Galaxy Stats, too, I believe? They are enabled (I forgot to disable them), but none used.
However, at the end of the prior game, I 'had' cheated, namely spawning a few hundred Omega Drives on an AI homeworld, and got to see the Imperial fleet collide with nearly 200k AIP. Imperial Fleet still won.
In this save, they just start glassing every world, spreading out. They were not controllable; they are listed as a minor faction. They don't hit anything with +AIP, they just hit Guard posts and enemies. However, since it's the beginning of the game, they pretty much wiped a full cluster out with not even a dent. They started getting stuck in loops with my planets, too. Lots of unhandled errors.