Updated R5 pack in first post as it now should be usable in MP.
Hosting player still need ScriptAppDomain stuff and saved files etc will be on hosting player.
Clients should join squadron preferably in A-flight but not as flight leader.
B-flight should be usable too but they are parked (some might even prefer that I guess)
Haven't tried as client myself for obvious reasons but please report back any issues, there must surely be some.
(I've rearranged the menu stuff from what I learnt doing the AirWarfare MP set but most is still new grounds for me)