Ohh, that’s cool. How far do you want to go with this? I had the idea of using a custom wayland protocol to make per-app global menus instead of per-window so you can have an app open without any windows, like on macOS, in the compositor I wanted to write. However writing a compositor using wlroots is still incredibly difficult if you have no prior experience so the whole thing didn’t get very far yet. If that’s something you want to do too, I’d be very interested in this.
(Speaking of, why did you decide not to build this on top of wlroots?)