Well, that worked and the VM booted.... Windows joins domain, and.... /something went wrong, redeployment required/. No desktop, no apparent way to check for errors. We're beyond the scope of this thread. Thank you!
Serendipitously, someone from Netwrix called me soon after that. I told him I know the big two commercial virtualization names are supported, but all this /can/ be imported here... I also gave him a quick elevator pitch on XCP-ng, for as much good as that might do with a kinda new sales guy. From here on out, if their engineers can't help, I'm off to find something else. 🙂