Very few are aware of linux-hardened let alone hardened-kernel.
https://github.com/anthraxx/linux-hardened and hardened kernel config (at least host) should be suggested to openwall kernel-hardening mailing list, other related mailing lists and other Linux distributions too.
- https://lists.debian.org/debian-devel/
- https://www.openwall.com/lists/kernel-hardening/
- https://github.com/minipli/linux-unofficial_grsec
- https://blogs.gentoo.org/ago/2017/08/21/sys-kernel-grsecurity-sources-available/
- Fedora
- gentoo
- arch linux
- Tails
- Ubuntu
- GrapheneOS
- Qubes mailing list
- https://www.linuxmint.com
- https://trisquel.info
- https://mirage.io (might not be aware of linux-hardened)
- https://nmap.org/mailman/listinfo/fulldisclosure
- https://mailman.stanford.edu/mailman/listinfo/liberationtech
Most of them were previously interested in grsecurity but I don't see discussions on linux-hardened let alone hardened-kernel.
Ideal outcome: another distribution adopts hardened-kernel.
Very good outcome: more awareness for this project and new contributors joining linux-hardened and/or hardened-kernel project.
site:gentoo.org "linux-hardened"
site:fedoraproject.org "linux-hardened"
site:mirage.io "linux-hardened"
archlinux heard about linux-hardened but not hardened-kernel.
https://wiki.archlinux.org/index.php/Security#Kernel_hardening
Similar to previous outreach:
https://www.whonix.org/wiki/Hardened-kernel#Upstreaming