X7 stations are subject to the same size limitations as factories.
1.1/ What is Production
Production is the creation of ships, vehicles, items, weapons and droids in facilities and space stations. All ships may be built in shipyard space stations (see Stations Rules) if the ship is the length of the station or smaller (doesn't apply to stations 3km or larger). Factories and factory stations are limited to ships less than 80 metres in length.
All Boats and Submarines are produced in Naval Shipyard facilities. All medical items are produced in Labs or Medical Factory Stations. All other ships, vehicles, items, weapons and droids are produced in factories or factory stations.