The GC2 system worked well enough:
- It needed a build-queue, just like a planet. So you could just point your constructors at it as a "rally point" and have it work automatically until you finished out the build-queue.
- Starbase tech didn't keep up with ship advances. A starbase (in my mind) should be competitive with even the largest ship hulls if you invest the constructors into upgrading it. In my mind, a military starbase should be able to fend off multiple of the largest ships.
- Maybe we need multiple sizes of starbases that have to be researched. So that late-game starbases match up with the late-game ship sizes.
- Constructors being vulnerable to attack during movement to the starbase was a good feature.
- Starbases need a better UI where you can decommission unwanted elements in order to make room for new elements. (I view starbases as being "mini" planets with special buildings.)