I'm also a heavy user of an X-only window manager (xmonad). Learning about this makes me wonder if I should start learning how to work with another window manager so I'm not caught off guard when something stops working.
I'm really attached to stumpwm, which is also X-only. We have been hearing reports of the pending death of X for at least the past decade, so I'm never certain how seriously to take them, but I've kept an eye on what looks like the closest thing to a wayland implementation of stumpwm (https://github.com/malcolmstill/ulubis).
You could try to transition to the sway wayland compositor (which is largely compatible with i3wm) or maybe to https://github.com/letoram/arcan which is a lot more programmable than sway