I didnt know these existed!
What is this? These are images based on ublues "starting-point" toolkit to create modified variants of Fedora Atomic (the name for all atomic, immutable etc distros).
This means everyone can create the Distro they prefer, with programs, settings, services, udev rules, wallpapers, hardening etc. exactly as they want, while keeping just these diverging from upstream.
Have a look at this, Linux Mint ;D
So these images use GrapheneOS'ses hardened kernel, maintained by anthraxx and the hardened memory allocator maintained by the Divested Computing Team and GrapheneOS
So the result is a project with somewhat of a difficult (but currently working) 3rd party dependency, but the result is very close to upstream and a drop-in replacement.
Just like with ublue, all you need to do is rebasing to the unsigned image, rebooting and rebasing to the signed image. The guide is in the repos!
Its important to test it, and help the developers maintain the components!
Harden my Kernel, daddy