The bottom line for MMT is that it is still a form of a ‘managed’ economy. The manager would be Congress. It would appropriate whatever spending it wanted and the necessary amount of money would be created to fund that level of spending. If inflation did start to rear its ugly head Congress would deftly step in and raise the appropriate taxes by the appropriate amount to draw the appropriate amounts of money out of the appropriate sectors of the economy in a timely fashion. What could possibly go wrong?
For the record, I have my own revolutionary alternative that I have developed, one that would make the supply of money (as currency) and the existing economy as a whole completely self-regulating: “For Crying Out Loud, ACCEPT That A SOLUTION Actually EXISTS” (a “2 min read” — including options for further reading — here in Medium). If it matters, I do have an M.A. in economics.