learning the init cli is simple. s6-rc is similar enough to openbsd rc that it should be fine
the hard part is installing all of its very modular components correctly which may or may not require grabbing somebody elses packages and updating them and writing all the required services (im unfamiliar with execline which is kind of a requirement here)
theres a lot more going on than just learning the interface. theres a reason i was initially intending to install exherbo vanilla and then work on my own distro that uses s6 by default (and busybox including mdev, and musl probably, but still gcc. basically id make source-based alpine linux but with s6 instead of openrc because i dont like openrc's cli)