"MP NOTES:
This mission can be played in coop. Regarding the nature of the DUWS, it must be run on a listen server. Does not work on a dedicated server. I suggest adding a password to your game, so only friends can join and no random guy will be able to trash your game."
So have you looked into DUWS working on dedicated servers! I have been running servers for Arma2 and our clan is moving over to Arma3. We been running DUWS mode on our Clients and would like to push this to our dedicated servers!
DLLKillem