See related sibling: the use cases are compelling!
My complaint is that tmux handles them perfectly. Exactly the claim that OP is making with their software - is served by robust 18 year old software.
In 2026, it costs nearly nothing to thoroughly and autonomously investigate related software — so yes I am going to be purposefully abrasive about it.
And if you want to interact with tmux from within the python interpreter there is a very good library available, libtmux: