I've started using ewm to get this kind of unification between emacs window management and non-emacs window management.
I keep trying it (coming from EXWM) but I get lots of lag, stutters, and poor fractional scaling. I'm not sure how much of that is "GTK under wayland", Emacs's PGTK build (known to have lag/rendering issues), AMD kernel drivers (?), or EWM itself; but it's not yet a replacement for EXWM in my experience.
"Writing a Wayland compositor from scratch is a staggering amount of work..."
I switched to Wayland and sway about 2 years ago and it hasn't been bad, but this is the thing that makes me most sad about Wayland. X has so many different window manager options, it's like, an embarrassment of wealth. Wayland has like, 3 "finished" ones (if sway even counts).