Do AI empires get a "cheat" boost in a (defensive) war in the MegaCorp DLC?

Solution 1:

Yes, it seems that there is such "feature": AI fleets have a much bigger than expected chance to disengage

Space combat has been re-worked. Every ship has a small chance to survive catastrophic damage and disengage from the fight. New backup consoles can increase your chance. Certain empires that have a speciality in backup technologies will also boost that chance.

This can be further boosted using admirals with Trickster trait (+25% disengage chance) and the "Hit and Run" war policy (+33% disengage chance).

This can make wars longer and bit more difficult since you can't decide everything in one big battle. But there are few ways to counter it: devices that reduce the chance of disengagement (available on Titans and starbases), fighting in black hole regions and PROBABLY by increasing the size of the weapons (if you can take the enemy ship in 1-2 shots, they won't have time to disengage). You can also reduce the overall effect by trying to rush enemy ports