You would probably have to change your keybindings a little but otherwise it's very similar... before the Wayland part
Switching from i3 to Sway kept 90% of the same config for me, changing only keybinds and output configuration.
I did have to override args/env for some things to truly do Wayland, but that's shortening every day
I'm increasingly tempted to grab a simple Wayland compositor and "bolt on" a minimalist X implementation directly on it to also allow X connections with just enough of the protocol implemented to allow running some simpler X WMs (but I'd love it if someone beat me to it).
For WMs with lots of fancy stuff it'd can take quite a bit of the X API to support, but a simple X WM doesn't typically use that many request types (I just looked at i3's source, and it's X interactions are pretty simple...