I, of course, agree that the term "coin" can refer to any material and even cyber. Coins do not have to be and never have had to be metal except where a supreme law specifically stated or states metal or a particular metal or particular metals. The problem is in convincing so-called Strict-Constructionists and/or perhaps so-called Originalists and getting around the evil, lying ones throughout government and at the major corporations and greedy think tanks, etc. Some do conflate Sections 8 and 10 of Article 1 of the US Constitution. However, it sounds like we are getting closer to sanity/consensus.
"Coin" is a verb and is a concept. That's why for all practical purposes, we can coin paper and even cyber money/currency. Frankly, we also could and should legally bypass the Fed altogether.
The new United States Notes (debt- taxes- and interest-free) should be issued directly by the US Treasury without any platinum coin having to run through the Federal Reserve. I'm okay with the platinum-coin plan though if that is closer to the people's ability to grasp the concept and grasp that it would be completely legal.
We should also pay off the National Debt completely while not enriching any fraudsters/banksters. We should guarantee that no pensioners or others fall into bankruptcy, homelessness, starvation, or even poverty as a result (it would be easy!).
We should have a new monetary authority that is a non-politicizable, opensource, computer algorithm that would completely control the money supply to avoid all price inflation/deflation in the aggregate and such that no necessities of life would ever become unaffordable for any citizen. We should have pure bottom-up grassroots democracy where a fully informed public makes the choice for what they want to do collectively, what to fund, so to speak. They would have to do the work, but they already are.
There is no lack of money, ever! There are only banksters standing in the way with their hands out for a cut during money creation and for doing nothing to earn their disgustingly piggish, evil share.