Thanks for the feedback!
Maybe I worded my question weirdly, I meant more that "In terms of core features how high does multiplayer support land?" But now that I think about it, I have most of what I consider "core features". That's my bad.
Since it's my first mod I limited the scope to single player so I could release into a sort of beta. Unfortunately multiplayer support will require a lot of changes to the code. I am slowly working towards it though; the last release didn't have many features, but I did spend about 10 hours refactoring partly to fix a scroll bar bug and partly to prepare for refreshes to windows in multiplayer.
I'll try to do some testing and research into how long the multiplayer update will take, then I'll make an announcement post with a timeline.