Jonas Heinrich took to a Firefox branch maintained by Red Hat developer Martin Stransky to getting it working on Arch Linux, getting the Firefox build into an AUR repository, and also producing a Flatpak build of the Wayland-patched Firefox.
With his firefox-wayland-git package via AUR, Firefox can run without any usage of XWayland. This is as upstream Firefox continues getting closer to landing all of the Wayland support upstream so it will be an out-of-the-box experience in the hopefully not too distant future.
After getting the patched Firefox on AUR, he took to making a Flatpak package of firefox-wayland-git too, making it easy to deploy on other Linux distributions. All of the details for those interested via this blog post.