I'm a browser implementor and I agree, this proposal doesn't have enough value to be worth doing. Inventing a password field UI that is unforgeable is hard, use

I'm a browser implementor and I agree, this proposal doesn't have enough value to be worth doing. Inventing a password field UI that is unforgeable is hard, users will stay used to normal password fields, and it is easy to forge a regular password field using JS. Therefore this proposal won't help with phishing, and that seems to be the only area where it has a hope of helping.