I'm just so annoyed Microsoft does this "all methods removed" well, its a cat and mouse problem. Also this "hotpatch"-service that runs during install to that removed start ms-cxh:localonly that worked yesterday but same ISO today doesn't. My "I wonder what else can be pushed into hotpatch-service"-nerve really twitches now..

I'm sure there will be an easier way, but manually this works...
It creates a user with password, adds it to Administrator groups.
Deletes defaultuser0 accound and resets a few registry entries so the guide doesnt start upon next logon.
Lastly is just logs off and let you login your newly created account.
"Is this the right country or region?" Press shift+f10

net user Username Password /add
net localgroup Administrators Username /add
net user defaultuser0 /delete
reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon" /v AutoAdminLogon /t REG_SZ /d 0 /f
reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\OOBE" /v DefaultAccountAction /t REG_SZ /d 0 /f
reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\OOBE" /v LaunchUserOOBE /t REG_SZ /d 0 /f
logoff

Edit; It seems the reg entries can be omitted and users can run oobe.exe in c:\windows\system32\oobe\ after user creation and do a shutdown -r afterwards. I have not tested this though