Neither of those functions are something Kubernetes does itself at all. For clusters to have that kind of functionality it's usually implemented with something like cluster-autoscaler. If it's not implemented with cluster autoscaler there's a chance you have a really annoying experience when nodes go away since the orchestrator doesn't know and takes a while to decide the node is gone and things should be cleaned up/rescheduled.

Now that info aside, they do support cluster autoscaler.

https://www.digitalocean.com/docs/kubernetes/how-to/autoscal...

Or maybe it's more appropriate to say that Cluster Autoscaler supports them? This tool (CA) does scaling in both directions and is highly configurable. At least, it is for other cloud vendors so I'd guess it's going to be so here too.