@nikade Thanks for your comments and thoughts. We're repurposing existing HP DL380 servers for the hosts, and was going to try repurpose our Nimble AF40 arrays, but they only do iSCSI, which means thick provisioning, which creates a capacity challenge for us (some of our VMs have been provisioned with 2-4TB virtual disks, but only using 100-300GB... so recreating smaller disks and data-cloning would be tedious but necessary).
TrueNAS is my 'gold prize', assuming it provides enough uptime and performance. Our IOPS and throughput requirements aren't huge; they only hit anywhere over 500MB/sec and a few thousand IOPS during backup jobs.
Replicating XOA is definitely a 'default'. But from my lab tests, redeploying and restoring config is to quick too, so I'm not too fussed about 'losing' XOA. I'd backup the config to on-premises 'remotes' and to cloud-based object storage.
Much appreciate your time and feedback, thank you!