I don't know about interesting, I think Niri from the parent looks like something I'd like to try.
I've used i3 and moved to hyprland (because it's pretty).
From the perspective I was coming from, I don't think it matters that much, you'll run into the same issues with any of them.
It's about understanding all the things Gnome/KDE/Xfce etc do for you, and how you can set that up differently yourself using components of your choice.
wmii[0], it implements the acme window layout. But the interesting part is that it exposes its state as a file-system. The main loop is a shell script[1]. So BYO posible, fe here is a Ruby one [2]
