Hmmm, with the new code it now no longer storage migrates the Template/VM and errors with:

$Error[0]
Exception calling "RelocateVM" with "2" argument(s): "Invalid configuration for device '13'."
At C:\Users\jmilano\Documents\PowerShell_Scripts\Datastores\2023-03-04 NetApp Datastore Migration\Storage-MigrateTemplates.ps1:150 char:9
+         $vmView.RelocateVM($spec, $null)
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : VimException

I think this code exposes the "real" issue- that the connected portgroup to the template is not valid. I fixed the above issue by disconnecting the network from the VM and converting it back to a template and the script storage migrated it OK.

I'll keep testing to see what happens with the rest of the templates.