The host prefix on an existing OCP 4 OVN cluster can't be changed as a Day-2 operation as per the documentation.

--> https://docs.openshift.com/container-platform/4.14/networking/configuring-cluster-network-range.html#:~:text=an%20installed%20cluster-,The%20host,-prefix%20cannot%20be

That parameter is very crucial as it decides how many pods can run on a single OCP node. Currently, the customer needs to get a support exception with detailed steps to change the host prefix to fulfill the requirement and keep the cluster in a supported state.

 This parameter can be changed officially in a supported manner during the SDN to OVN migration process only.

--> https://docs.openshift.com/container-platform/4.16/networking/ovn_kubernetes_network_provider/migrate-from-openshift-sdn.html#:~:text=spec%22%3A%20%7B%20%22networkType%22%3A%20%22OVNKubernetes%22%20%7D%20%7D%27-,To%20specify%20a,-different%20cluster%20network

It will be very helpful if we can provide a supported method to customers for changing the host prefix as a Day-2 operation.