Just hit this problem as well. To help others on this issue, what you are saying is this will not work:

{
  "kind": "StorageClass",
  "apiVersion": "storage.k8s.io/v1",
  "metadata": {
    "name": "do-block-storage",
   [...]
  },
  "provisioner": "dobs.csi.digitalocean.com",
  "reclaimPolicy": "Delete",
  "volumeBindingMode": "Immediate",
  "allowVolumeExpansion": true     <== What you are saying is this will not work
}

I was able to increase the Droplets storage, and increase the PersistentVolume: spec/capacity/storage but not able to increase the PersistentVolumeClaim: spec/resources/storage. It produced the error:

"persistentvolumeclaims "[redacted]" is forbidden: only dynamically provisioned pvc can be resized and the storageclass that provisions the pvc must support resize". 

This is because, as you said, allowVolumeExpansion, is not supported.

Other than reinstalling a new Kubernetes cluster (no snowflakes here) with new and larger storage, is there a workaround or suggested alternatives?

This would be useful. Is it supported?

Hey friend,

Sorry for the delay on this. This feature is not currently supported on our side.

Jarland

DOKS version 1.16.2-do.3 and later supports volume expansion / resizing:

• https://github.com/digitalocean/csi-digitalocean/issues/106
• https://www.digitalocean.com/docs/kubernetes/resources/volume-features/