>To login, you just scan the QR code from my authenticator and enter your phone's pin or use Face/Touch ID

Others see the problem with having to scan your QR code while using the device that, presumably, needs the QR code scanned ... you've just mandated multiple devices

You might look at SQRL (https://www.grc.com/sqrl/sqrl.htm)

Or just use "normal" TOTP systems like the myriad authenticator tools already out there