I can test it. What would be the advantage if I use it in my tool instead of Ubuntu? At the end of the day with Kubernetes I don't think it makes much difference which OS you use. I picked Ubuntu because it's standard and servers with this image build very quickly with Hetzner Cloud.
CoreOS (and its spiritual successor Flatcar) are immutable, which gravely limits the silliness that can be done to them post-launch. We use now use Bottlerocket since we're on EKS, but it's even more locked down since to even get an interactive shell is some major hoopjumpery. I believe Talos goes even further and is completely devoid of a shell
So, yes, it absolutely matters which OS you use, of course depending on your threat model and tolerance for "no, you don't get to ssh onto a Node and do whateverthehell you want"