In the systemd-love overlay, I committed app-admin/eselect-settingsd and a modified version of sys-apps/systemd and app-admin/openrc-settingsd (which got USE=systemd removed).
In order to make the transition to systemd smoother, eselect settingsd allows users to switch between systemd provided settingsd dbus services and openrc ones.
The design is simple (it just installs the shared files between openrc-settingsd and systemd into /usr/lib/eselect-settingsd) and I believe it is an improvement over the current situation.
The overall plan would be to make the transition from/to systemd easier for the end user.
[settingsd eclass] https://github.com/Sabayon/systemd-love/tree/master/eclass/settingsd.eclass
So what do we do with this? This avoids the conflict between openrc-settingsd and systemd.
With my latest patches to systemd, eselect-settingsd is no longer needed and has been removed from systemd-love.