That’s not a solution, because that’s not what it says. “You have the right to remain silent. Anything you say can and will be used against you in a court of law,” (bolding mine).
I should surprised you of all people, who claim to be a textualist, are making this argument. You’re the one that says that words mean what they mean.
But, it’s not surprising, since, as I said, the study of law and logic don’t go together. You haven’t even been taught that you need to be consistent with your assertions. You’re taught the opposite, to argue whatever flaws you can find, even if it contradicts what you’ve said before. That’s providing a rigorous defense.
The point is that you have the right to remain silent has now been proven false. You do not have the right to remain silent. You have a right to tell people that you want to remain silent, otherwise even your silence can and will be used against you in a court of law. Not just anything you say.
Of course it’s not mindblowing to you if you invalidate one of the premises. I can’t help it that you haven’t been trained to notice when you yourself move the goalposts.
No, IMO, you are in custody, as you are not free to go, e.g. Berkmer v. McCarty/Pennsylvania v. Bruder, in custody, but not custodial for PURPOSES of Miranda only.
There is no “it”. Miranda warnings vary between jurisdictions, and are not controlling law. They are guidelines based on, but not directly taken from, the language of Miranda v. Arizona and its progeny.