That’ll work really well when you go into a Taco Bell and try to buy something. They called the cops on this guy who tried to pay with a two dollar bill. Even when people are educated with the new policy you’ll still see things like that. And then, how will the merchant calculate how much the gold or silver is worth? And what would they return as change?
It’s meaningless.
Nobody is going to use a $1700 coin with a legal tender value of $50 to buy anything. The change would be in notes or bills, same as would be anything else.
You could buy 4 tacos for a silver dime! :)