btw, just as an example, the CT adventure The Kinunir includes the following Library Data entry:
General Shipyards: The largest starship manufacturer in the Regina subsector, with yards at Regina, Efate, and Pixie. Originally a military contractor, General no longer produces ships for military use, instead concentrating on the more lucrative commercial market. The yard at Regina is capable of producing ships up to 5000 tons, while the subsidiary yards at Pixie and Efate are limited to 600 tons per ship, and devote most of their attention to annual maintenance.
While this was written when 5000 dtons was the largest ship out there, it serves as a useful example of how just because a starport is class A, it does not necessarily have unlimited production capacity. Although Regina, Pixie, and Efate are all class A starports with naval bases, all the capital ships are built at Regina, while the 'adventure class ships' are all that can be built at the other ports.