virt-v2v should support editing image in-place without moving to export-domains or libvirt etc.
The operations I imply are: adding VirtIO drivers, changing REGISTRY, updating initrd etc.
Should be fairly easy to implement: no new code required. Am I right?
You can run virt-customize on the guest after conversion.
Or virt-win-reg for registry changes.
I'm closing this as this is now supported upstream.