Remember small stations are in the most cases the closest ones to fields, barge with docking restricted only to shipyards would be unbalanced. Not great problem for example for IMG or BMM (Aland/Southampton, only one jump away from mining systems, in case of IMG even in that same system), but e.g. DHC with Oder shipyard 2 jumps from O-7 or O-11, that would be just unfair.
Barge is already nerfed enough, leave it as it is.
