I don't remember exactly what kind of browser it was - either safari or chrome, but during the registration process, a window popped up that Google wanted to scan my key type. And I refused to give Google this right by clicking the corresponding button.
And to my surprise, after this, i could not complete the registration of my Trezor as a two-factor authentication key. Perhaps precisely because I refused to provide information about the parameters of my device.
Why would this surprise you? It's like acting surprised that you don't see any video if you deny access to your webcam And to my surprise, after this, i could not complete the registration of my Trezor as a two-factor authentication key. Perhaps precisely because I refused to provide information about the parameters of my device.
If you don't grant permission for the browser to be able to talk to the USB device, how is the USB device meant to communicate to the website? 
On another note, something I found somewhat interesting was that during my experimenting with the dropbox 2FA security keys, originally a Windows/Microsoft authentication dialog popped up when I was trying to add a security key... so, it was trying to use some sort of Windows/Microsoft account based authentication... I could use my Windows 10 "PIN" as my 2FA key??!? Once I removed that, and then cancelled that dialog on the next attempt to setup a 2fa security key, it then moved to using the hardware key.