Change number of replicas for hidden and restricted indices

Is there a proper way to set the number of replicas, either explicitly with the index.number_of_replicas setting or with the more dynamic index.auto_expand_replicas setting for hidden and restricted indices.

The goal: Set a minimum of 2 replicas for security, ism, kibana indices.
Do not change the number of replicas for other / data indices.

Preferably manage this automatically at a cluster level, with ISM, a template, or other.
But what is the proper way to manage this?

Examples are:

  • .opendistro_security - which seems to have auto_expand_replicas set
  • .opendistro-ism-config
  • .kibana, .kibana_1, etc

I’ve tried applying an ISM policy to manage this but I’m then getting an “errormessage” of “Matches restricted index pattern defined in the cluster setting”. Fine I guess, would be sad if a misconfigured ISM setting deleted the security index.

But is there a way to manage this - for these indices - in a controlled manner?