It looks like the use of https://update.nitrokey.com to install the update is not possible under Windows 10. All Browser will get stuck on a 2FA Popup (conformation request) from Windows itself and will run into a timeout.
What worked for me was using Ubuntu. The upgrade finished in 1 minute.
There is still no way to locally login into Windows without using Third Party Software right (outside of an AD Domain)?
P.S: Why is the News about the 2.0 Upgrade not part of your Blog Feed?