If you're just looking for init and service management, the S6 system (and its wrapper 66suite) are pretty good. It's the only alternative that seems to match Systemd for feeling like a modern tool in my opinion, rather than a relic of the old days.
Better to stick with INI v1.4 format.
EDIT: Ah, you might mean https://skarnet.org/software/s6-rc/s6-rc-compile.html -- that indeed is getting to be weirdly complex.