[Aeolun]

Why would you think the master password has many special symbols and 20 characters? You can just have the 4 digit pin as your master password.

[eviks]

Your mirroring fails precisely because it's a password, and it's pretty common to set minimum requirements, so you can't have 4 digit pin

Similarly with your first point - I don't think the master password has many special symbols, I'm just asking a question that illustrates the issue with the original faulty assumption