These discussions are very intellectually interesting, however, the real economic issue is does the money system facilitate commerce, stability and equitability, i.e. practicality, security and ethics.
IMO MMT has the mechanics of money correctly described, but precisely like what neo-liberalism did, is still an ideology looking for justification. Personally I think libertarians/free banking are headed in the wrong direction and that the money system requires governmental sanction/justification. But MMT, like neo-liberalism, still fails the stability and ethics requirements.
Until such time as MMT or any other theory recognizes and properly understands the concept behind the new paradigm of Direct and Reciprocal Monetary Gifting they will be incomplete, inadequate and effectively unable to fulfill all three requirements.
Wisdomics-Gracenomics: The Natural Concepts Behind The New Paradigm of Direct and Reciprocal Monetary Gifting