Hetzner Cloud is officially supported, but that means setting up VPSs in Hetzner's Cloud offering, whereas this project was intended as a more or less independent pure bare-metal cluster. I see they offer Bare Metal support as well, but I haven't dived too deep into it.

I haven't used KubeOne, but I have previously used Syself's https://github.com/syself/cluster-api-provider-hetzner which I believe works in a similar fashion. I think the approach is very interesting and plays right into the Kubernetes Operator playbook and its self-healing ambitions.

That being said, the complexity of the approach, probably in trying to span and resolve inconsistencies across such a wide landscape of providers, caused me quite a bit of grief. I eventually abandoned this approach after having some operator somewhere consistently attempt and fail to spin up a secondary control plane VPS against my wishes. After poring over loads of documentation and half a dozen CRDs in an attempt to resolve it, I threw in my hat.

Of course, Kubermatic is not Syself, and this was about a year ago, so it is entirely possible that both projects are absolutely superb solutions to the problem at this point.