From: Georgetown, Texas, USA
How the Minimum Shipyard Size is adjusted (if at all) by Naval Support or other means I do not know.
It's not. If a minimum shipyard size is specified, it must be present. No ifs, ands, or buts.
If a minimum shipyard size is NOT specified, the accumulated capacity of the port (by size), shipyards, repair ships, tenders (if appropriate) and naval support must offset the size of the ship.
If appropriate means the right kind of ships for the tenders. Subs/Sub Tenders, etc.
Capacity means a calculated value based on port size, shipyard size, amount of naval support, presence of repair ship(s) and tender(s). The exact formula used may not be in the manual and I am not authorized to publish it.