Launching a dedicated server in wilderness mod seems to still cause the florid postern to appear and be the starting point for joining players. I have made wilderness servers before and this was not an issue. No change was made to the cluster.ini files, and when checking the game in the DST server browser it is listed as wilderness.
Deleting said florid postern causes the game to crash
Set a dedicated servers cluster.ini game_mode = wilderness. launch game and join