I recently moved from Kitty+Tmux to Tmux only setup. I think the maintainer has implemented most of the features in tmux like split panes, switching, changing layouts etc and is probably why says what he says.

For me, I've found Kitty quite configurable enough to have everything except the remote server thing. I used this as my guide: https://www.reddit.com/r/KittyTerminal/comments/z2p2sh/ditch...