I don't even remember the last time I had to input a security question, so personally I wouldn't have wanted them to waste their time with such a feature. Isn't the feature inherently moot when you're saving the answer in you password manager? The only way to forget your password is if you're unable to access the password manager, which also contains the answer to the security question.

At that point you're just as secure inputting any random letters to effectively disable the security question unlock.