Being the freak that I am, I went the whole way. Did the standard upgrade route. No real problems. Went through the media creation routine and held it whilst I copied the install ESDs from both folders, and made ISOs from them, then allowed the media creator to continue. and install Windows 10. Now I want to try the self made larger ISO (larger as it included extra updates, I believe) , just from curiosity, to see what it offers for a key. The upgrade path has given me a new key, as expected.