Currently we have the good option to log in with the master password and a YubiKey. This combination thwarts keyloggers, onlookers and anyone who steals one device and not the other.
I propose that the unlock feature provide the option to unlock using a PIN (short and at risk of onlookers, but still allowing only 5 attempts before logout) and the YubiKey. This combination would allow a fast unlock while still thwarting keyloggers, onlookers and anyone who steals one device and not the other.
Note: I am not proposing to unlock using the Yubikey alone, because the unlock also needs “something you know”. I am only proposing to allow the unlock operation to mimic the most secure login operation, except for using a short (and fast) PIN instead of the long master password.