I'm gonna try installing on another PC that hasn't had W7 on it then do slmgr.vbs /ato and see what happens.
You can do ... but outcome is known, since the Upgrade uses a set of generic Retail keys. And: THERE IS NO KEY NEEDED AT ALL! The Hardware ID (HWID) acts as unique key for this Upgrade. IF ASKED FOR A KEY; SKIP OR DELAY!! .
Supposedly you can now clean install windows 10 from media and keep the activation But it's better to do it through settings and perform a reset on the pc
so theoretically you could skip having to upgrade no os installed at all just clean install no key skip then slmgr.vbs /ato
I don't have an address. The switch for /skms require a valid server but there doesn't seem to be any available at the moment I guess just use MTK or something like that...