That legal clarity is why those fussy arguments against the coin are nonsense. If Congress fails to raise the debt ceiling, in effect it will have said Biden must spend, can't borrow, but can mint the coin. Arguably the coin is not just an option for him, but a necessity — there is no other way to avoid breaking some law.(The other obvious gimmicks involve the Fed saying, as it does occasionally, "we have a button that can make a kajillion dollars when we press it and the legal right to use emergency powers to stop the economy from blowing up, so, lol, whatever it takes.").
The coin discourse is amusing because it highlights a few things: money is fake, many constraints are self-imposed by custom more than law, and pointing these things out makes people really fucking mad.