Fedora 29 has a “firefox-wayland” package that runs the latest stable release of Firefox (63 as of now) on Wayland (instead of XWayland). I’ve been using it for a long while and it’s been great!
It is not for the first time, that Fedora package had something enabled before the upstream package did: CSDs went the same way.
Also, without XWayland I have no artifacts when scrolling fast in long documents. Very nice :-)
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1585393
[2] https://bodhi.fedoraproject.org/updates/FEDORA-2018-2d42997a...