No idea about ClusterOS, but I would recommend IncusOS if you're looking for a nice clustering solution. Incus has become indispensable in my homelab over the past few months. It's what I put on my bare metal machines and then spin up Talos Linux VMs for day job practice.
How does the IncusOS API compare to Talos? When I first looked at it it seemed very minimal and I didn't see a lot of options for more complex installs (eg network bonding, disk partitioning).
I really liked IncusOS but it still felt quite primitive compared to Proxmox. I also didn’t really like the way it bundles VMs and containers into an ‘instance’ concept, it made the UI and management via Terraform confusing. Had a lot of problems with the TF provider too.