Mosh doesn't play nice with wemux specifically or tmux as a whole?
Glad you liked it, in any case! I'd love to hear any comments/questions/suggestions anyone has, I'd like wemux to be as good as it can be!
I actually wrote a script called wemux (https://github.com/zolrath/wemux) specifically to enhance tmux remote pair programming. Adds user/server listing, a concept of host/client, attach/detach messages and more.