I'm not seeing what this adds. This is the same thing as putting up 2 passwords and calling it 2FA (which it isn't). Under the vast majority of threat cases I can think of, you are either still screwed because they capture your login at the same time they capture your master password or you are stuck back with the problem of remembering a secure, non-guessable element for every account, which is exactly why password managers exist in the first place.
This is either ineffective, impractical or both depending on the threat you are trying to protect against. It's also trying to solve a problem that was already solved. This is exactly the reasoning behind 2FA/MFA and making sure that access to multiple things is needed.
It would be much better to get a Yubikey or similar and put your HOTP/TOTP secrets in to that so that it is physically isolated from your phone and the internet and thus can't be compromised without direct theft of multiple devices. You get the same advantages without the disadvantages and limitations of hanging your security on two of the same factor.