> is currently converging on a different proposal by systemd developers that's standardized by the UAPI Group

We're working in this space with Project Bluefin: https://github.com/projectbluefin/dakota

Both approaches are indeed competitive, but you can also leverage both to achieve the same thing. We're experimenting with a pure ddi Bluefin, a buildstream/GNOMEOS one that spits out a bootc image, as well as a Bluefin that is just a systemd-sysext on top of GNOME OS. Chef's choice!

There will be many ways to slice this problem -- my opinion is that in the end it will be how you design the infrastructure to make these and not the artifacts themselves.

We already have CentOS/Fedora builds alongside these, long term we'll see which ones end up being the most efficient. Buildstream is a tool which people should look at in this space too: https://buildstream.build/index.html