Linux-libre for RPM
I started an RPM repository for Linux-libre: https://rpmfreedom.org/ to go along with my APT repository, which has existed since 2011. I think that takes care of the big 2 package managers. Should I try any others?
Parabola already makes them for Arch-based distros. You could make xbps packages for Void Linux for me, then I wouldn't have to compile my own.
I heard some people talking jokingly about making systemd a snap package for Ubuntu. Maybe you could make the kernel a snap package?
Maybe Slackware, but idk how many people will use it (I'm not a Slackware user, that's just the distro with a different package format that came to mind)
Alpine would probably be the most useful I think, then Gentoo and Nix.
Also what about adding suse's open build system and launchpad repos as options?