I still think Starbases should be built like any other structure.

What is really annoying is the race against time to hunt down the SB constructor frigate before it magically turns into a rapidly growing Starbase when it had 50 hull left. The Vasari don't even have to move the constructor, it can turn into a Starbase as soon as it comes out of the Frigate Factory. And once the Starbase is under construction it is ridiculously hard to destroy before it is finished. You need massive firepower to take it down.

The constructor frigate should never disappear. If it is destroyed, the construction should simply halt for as long as a new one can take its place. You should be able to stop Starbase construction just like you can stop anything else from being built: destroy the constructors. I like it how SB's now take longer to build in hostile Grav wells but it's still absurd to casually build such a thing while being fired upon. If the constructors would be destroyable while they build they should be a little cheaper and the Starbase itself should cost more.

And I still think that SB constructors should be built at a capital ship factory. Cap ship factory could use another function besides building one ship once every blue moon. Considering the size of a Starbase the constructors themselves should be cap ship size.

edit to add: considering the Vasari don't have torpedo cruisers and their anti-SB weapon is their own SB, they should probably have a sneaky way to build the Orkulus in a hostile grav well. How about a research option that lets them safely build in phase space for an increased cost?