I had actually set it up so racial weapon techs could be captured analyzed and you can start to research their trees. This is based on incidents such as the Brakiri / Narn researching left behind Centauri tech and other such things. But many areas are still cut off unless you actually have the Centauri (or other) Racial trait. Some races (like the Drakh) are 'unstealable' all together.
PF and Oleg
Thanks for that little tip
I was looking at the older ai and I think the reason it had built larger ships was because Each ship had a broader range of tonnage, so it would just build the biggest ship available.