Although this increases security, it is very hard to verify user when you lose your mobile device. It has to verify by a push through app, a code through the app, or mobile phone number.
One day, sister mistakened my phone as her’s and took it with her. I use my phone for Duo during my job. All my work application depends on Duo. Without my phone with Duo app,I wasn’t able to access anything on an unfamiliar device. Made my job very difficult that day.
Good concept, but needs more verification options