Thanks to @volth and their chromium-git PR, I am now building Chromium for NixOS users with Ozone/Wayland enabled. The repo contains a screenshot, but it’s roughly usable.
Similar to nixpkgs-wayland I am building the package(s) and uploading them to cachix. However, nixpkgs-chromium is implemented as a package set, so as to prevent any potential rebuilds of Chromium if your channel and mine are out-of-sync.
Feel free to give it a shot and file bugs on Chromium (or the package set) where appropriate. I’ve already opened one for video playback.