BSD users might also like Void Linux, which was developed by xtraeme (a NetBSD developer). It has glibc and musl versions and uses runit as an init system. You can also build packages from source using xbps-src.
The system also has no relation to ChimeraOS, besides the unfortunate name similarity. ChimeraOS used to be called GamerOS and renamed itself to ChimeraOS later; however, at this point Chimera Linux was already in public development with its name in place.
https://chimera-linux.org/docs/configuration/services
Then if a Linux kernel isn't a strict requirement, there's obviously NetBSD, from which Void takes inspiration. At last it's "the real thing" and not some adaptation, and a very underappreciated and overlooked Unix.
that said i was a freebsd user for over a decade so it must have left some mark (even though generally the systems have little to do with each other in their general design)
There does seem to be a lot of BSD influence over Chimera with the BSD userland, Clang / LLVM toolchain, lack of glibc, and cports.
Regardless of the inspiration, the design choices in Chimera are great. Being able to standardize on things like Pipewire and Wayland without legacy. Working to bring the functionality of systemd without the monolith is great too. I hope Turnstile catches on.