I'm sure your suggestion is more useful for people using a laptop-like chromebook, or have a keyboard attached.
But we are using the Asus Chromebox to stream video to a TV, and have the Chromebox attached to the back of TV.
I can just see the Chromebox usb ports, and that's all I need for the green light of the Yubikey-Nano (so I know where to touch for the static password).
A static password is required to login by Google's Chrome OS, and this is due to drive-content being encrypted.
And as you pointed out, Chrome OS allows a great many options for secondary passwords/verifications.
But a secondary password is definitely not desired (by me) since I don't have a keyboard on the Asus Chromebox, and I only use it to stream movies.
I do wish Google's Chrome OS had otp capabilities for the main password login.
Because I know other's who are now interested in this same setup.
And it would be much simpler if the Yubikey's OTP could be used for Chrome OS login.
In part because the Yubikey personalization tool seems to be daunting for the average person.
So if anyone figures out how to make Chrome OS accept the static portion of the Yubikey OTP as the login password...
then please post here and let everyone visiting this page know.
Thanks