The only issue I've had is their static snapshot of arch has some inconsistent dependencies from time to time that need manual handling, and occasionally they are missing a cert change so you either choose to trust the package from their server anyway and install it with a cert skip, or do without.
Aside from that, everything seems to work well, and if there were any problems, well I can always just reboot with the SD card removed.
I was worried about how /etc might interact with their stuff, but seems fine so far, and I assume they left it writeable for a reason. I do do backups just in case.
If you want to repackage distro binaries without recompilation, you can have a look here: https://github.com/flatcar/sysext-bakery/pull/74 There are two tools, one can bundle the needed libs in a separate folder, and the other one works more like Flatpak and uses a full chroot. Since you already know what files are needed at runtime I think you could try the first approach, otherwise the second might be easier.
We have indeed been playing with this! We think it's a great compliment to extending an ostree OCI base image and hope to bolt on all sorts of goodies. Lots of cool innovation happening in this space right now, it's awesome stuff.
https://github.com/flatcar/scripts/pull/1964
No I don't count Fedora CoreOS because it's a full immutable Linux distro. Flatcar is more slimmed down than CoreOS.
Red Hat has Fedora CoreOS and RHEL CoreOS variants. Flatcar is going strong with the CoreOS-ethos intact. Talos Linux is also pretty popular.
The cloud providers have various minimal OSes for use underneath Kubernetes clusters but not used for standalone machines. I think Rancher OS is no more but the rest of Rancher is ongoing. VMware's various minimal OS efforts are no more.
It's also super handy for writing out static Pod manifests to have replace the brain-damaging Ignition as a less stupid alternative to cloud-init
Flatcar inside Incus is a bit more difficult: for Flatcar being a container one can import https://stable.release.flatcar-linux.net/amd64-usr/current/f... and for it being a VM I don't know if the regular image works. A major hurdle is that one has to tweak the way VMs/containers are configured because normally Ubuntu's cloud-init is used but in Flatcar only coreos-cloudinit or Ignition is supported and there are differences in the way the user-data has to be set up and the contents as well. But in the end Incus would be one more "cloud" platform to support and one could make the Incus integration as nice as with other platforms where Flatcar runs on (OpenStack, VMware, etc.).
https://www.freedesktop.org/software/systemd/man/latest/syst...