They are basically just backups in case of emergency to access the cluster if Rancher is down. There is not anywhere to set a hostname for each node, and even if there was that’s not really much better because the set of nodes which are running the control plane can change at any time too.
So if you want a DNS name then you need to maintain a name and do SSL termination for it, as a single balancer that points to whatever control planes are healthy. See: Authorized cluster endpoint setup? .