- You can add ships for the frigate factory, as it has some free slots.
- Cruisers/capitals can't be added because the UI is stubborn and doesn't start filling the second available row, nobody's been able to figure out how to do it yet.
- You can add building types for available slots, but yeah, those are the only two production buildings.
- Ships are limited to 2 different strike craft, though you can have as many different types as you like to pick from.