Thanks for the feedback.
I did consider mapping an iSCSI LUN directly to the VM. Customer is using a Nimble iSCSI SAN and on a storage VLAN, which NFS is running over right now. I'd have to create a VM network to the iSCSI vswitch or just run iSCSI over their production network - I believe it's not recommended to mix production/iSCSI traffic. I do like the option of mapping the iSCSI LUN to another server if the VM/hosts go offline.
I'm pinging the forum to see if anyone else is running a similar configuration. This all started when I created a repository and Veeam said it didn't have 64K/REFS/no fast clone available. If i didn't see this, I'd never know about fast clone.