I'm still in the process of moving my workflow fully over to kitty, so I still use tmux a bit at the moment. Kitty multiplexing works decently out of the box for regular sessions, but wont work for sub-session + ssh.

Kitty comes with an integration script that you just have to run at the start of the session (put it in your rc file) for it to work in sub-sessions + shh. Haven't run into any issues with that so far.

So while I feel like I don't have enough experience with it to outright recommending one over the other, it's def worth checking out kitty if you're interested in changing up your workflow or are a bit of a minimalist and want to rely on less programs in your setup.