Curious what your use case is as opposed to using the official LAN support? For me, I'm trying to get it working completely without internet, ie on a plane. It's so sad to me that built-in LAN requires an internet connection.

not all participants had an official copy of the game.

while i think that it is well worth it, i am not the person who pressures other people to buy things for a single-digit-attendence one-time get-to-gether LAN-party.