I noticed something in a game for the first time today regarding custom races. Their starting system will always match the player's system. This doesn't seem right.
I played a quick game today with the Thalans against 4 custom enemies and 4 stock enemies. About half way through the game I noticed that all of my custom races had a PQ 15 starting homeworld, rather than the PQ10 and PQ4 I always have to play with as a custom race. That worked for me, I like to develop PQ15+ worlds, but it seems like a bug.
Just to test it further, I started a game with the Korx against all custom enemies, and just took the speed and sensor bonuses to scout the map quick. Sure enough, every enemy had started with a PQ10 and a PQ8.
Maybe this is for some sort of balance? I'd love to get the Korx starting worlds when I play as a custom. Or maybe it is a bug. In any case, thought I would let you know.