I have followed to VMware KB: Mounting VMware vSphere Storage Appliance NFS datastores on ESXi hosts manually to successfully mount existing VSA datastores to a host in a different Datacenter on a different vCenter server. In my setup vCenter-1 has the VSA cluster and vCenter-2 has a single standalone host. I mounted VSADs-0 and VSADs-1 in the standalone host in vCenter-2. I created a VM on VSADs-0 and ran the VM on the standalone host in vCenter-2. While the VM was running I shutdown VSADs-0 and the VM continued to operate.
I though this was all cool and assumed it must be supported but I now tried another test in regards to replacing a failed VSA node. After I powered off VSADs-0 I though I might checkout the Replace Appliance function of VSA 5.5 so I deleted the VSA appliance, shutdown the node and removed it from vCenter. I noticed that in the vCenter that has the VSA Cluster both VSADs-0 and VSADs-1 were still being presented perfectly but in the other vCenter-2 both VSADs-0 and VSADs-1 were inactive. Also after a short while a second VSADs-0 has appeared in vCenter-2. My environment is nested so maybe that effects the results but should sharing these VSA datastores across different Datacenters or even vCenters work properly?