Serious question: if one were willing to give up on curses, isn’t Emacs/elisp providing the best multiplexing system available to humankind? And conceptually, why would agents ever need to depend on curses?
The other problem is it does have to be hosted somewhere, and if you run it locally, it goes away when you close your laptop. If you run it remotely, you have the latency to the remote site. I suspect Superlogical is going to find a way to fix this problem.