I hope that "one a time" thing for Titans isn't hardcoded. From what I've found about Sins coding, you can't get a ship's special abilities without making it a certain class, so super-ships would have to be Titans to get Titan abilities. That being said, I hope that there's an easy-to-alter modifier somewhere for the max Titan cap, hopefully in Gameplay.constants, or even better, in each race's PlayerXXX.entity file, allowing modders to give different races more or fewer Titans depending on how powerful that race's Titan is.