I was recently playing as the Dominion, and when I first discovered the Borg in ~2200, I was disappointed to see that they'd actually LOST a war to another Delta Quadrant AI empire (Krenims, I think), had lost their fleet, and were being eaten up.

I'm not sure if this is actually common, but if so, I'd like to suggest a change to keep the Borg from being beaten back early in the game: strengthening their spaceports significantly.

Since no one else uses the Borg weapons tree (right?), this could be accomplished by giving some huge buffs to the Borg's default spaceport module: lots of extra armor, hull, and weapons, to produce a spaceport that's more like ~3k or even ~5k strength. Alternatively, just give them a cheap and very OP spaceport module tech early in their tech tree.

These much stronger default Borg spaceports would guarantee that the AI couldn't effectively take Borg worlds until much later in the game, and help offset their crippling weakness of losing a world entirely if it's ever successfully invaded.

Possible downsides: could speed up Borg conquest too much if enemy AIs throw their fleets into suicide attacks against stronger Borg spaceports. Could lead to extremely long drawn out wars if AIs defeat the Borg fleet, but can't get any real warscore, and won't or can't white-peace out.