The serverkit needs at least one ship, per ship class, per era, available at all times, otherwise AI matching goes loopy. Shipyard production can be modified by class so that certain classes are less likely to show up. It is not even necessary to restrict the C7 if these gf file settings are done correctly. They must be tested with the current map and econ values. Ships higher than the a CA class can simply be priced out of range for the shipyard for the shipyard to produce. No database errors or shiplist fudging. Restricting ships from appearing in the shipyard is only viable when there are still other ships of the same class being produced. This is not strictly done by the server, as easrly era has no BC class ships, but you have DN class ships that are in the same BPV range to compensate. On KCW, we will not have this luxury.