RHEV - Changing compatibility version of cluster

Hi,

Looking at this document:
https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Virtualization/3.2/html/Installation_Guide/Changing_the_Cluster_Compatibility_Version.html

Will it always be recommended to put hosts in maintenance mode before changing compatibility versions of clusters in RHEV?
It would be great to be able to upgrade the infrastructure without interupting the virtual machine's uptime.