> Would like to try my hand at building something like that myself, but X on top of being phased out is a strange beast to learn and there’s practically no material on writing something for Wayland.

You should look up the work of Sir_Cmpwn (aka Drew DeVault), specifically the wlroots project and his excellent writeup: https://drewdevault.com/2018/07/29/Wayland-shells.html