As I did manage to build E+EFL+DRM+Wayland on FreeBSD, after discussion with @raster on IRC, it turns out that currently E/EFL is tied to Linux-only syscalls and SystemD/eLoginD and won't run on platforms other than Linux. This sux :-)
There seems to be however a better solution already working out there called SeatD  and WLROOTS . It is portable by design and works on FreeBSD making Wayland applications like SWAY run with no suid. It also works on Linux. And probably will work on all other platforms out there.
This solution came from frustration at Linux "enforcing changes to be a progress"^TM (quote from Microsoft) so folks did not simply wanted to be a part of the problem. Very smart :-)