I can't speak to the Windows vCenter to VCSA migration personally, but full clone VMs should be easy if you want to do a side by side. It's linked clones that are unable to move and must be destroyed and recreated.
With a full clone/manual pool, if you're doing a side-by-side, you first make sure you have at least one shared datastore between both the old and new environments, and that the VM that needs to move is on that shared datastore. Then you delete the VM from the old View Administrator, but choose "Do not delete from vCenter." Then in the old vCenter, you remove the VM from inventory, and on the new vCenter, you add the VM to inventory. At this point, you would update the View Agent and tools to the new version. Then finally in the new View, you create a new pool and add your VM to it (or add the VM to existing pool). I'm sure PowerCLI could help you out with that process too.
The challenging thing about side-by-side migrations is that they're hard to do a little at a time unless you're fine with changing your naming conventions/View Connection Server name. Depends on your View architecture and your endpoint management system, whether changing the Connection server names and SSL certs an easy or complex process.
