I honestly don't think that there is anything that can be done at the moment. It's just frustrating now that the Modding Kit is released and you see all these fancy maps, but one can't really do anything on the gameplay side other than playing around with some small scripts.
I just don't get how TW is fine with hosting their Native Module as MP but is unwilling to deliver the server executables to the public at this point. I fully understand if it's unstable or even insecure, but they could at least release it in a way so you can host a server locally on your own machine which does not show up in the official server list. That way you can fully develop mp mods while if there are any security, stabillity etc.-issues no one is affected by that.
So at this point I actually hope that it's unwillingness to release rather than Multiplayer being in a really bad state, if it takes another half to full year for this to be delivered we might as well write our own PW standalone game.
For me the transparency is missing on that topic. I've yet to find something related to what's the state of self hosted servers. I don't even need a release date, just a "this and that is not working at the moment so we cannot release it right now".