"Admittedly, a sovereign government is never required to default as it can always “print more money”, though doing so is clearly unpalatable as it comes with high inflation and reduced future credibility. "

Your assumptions concerning "unpalatable" money creation in regard to inflation and credibility are just that, assumptions.

Inflation is entirely a product of available resources and labor, not the quantity of money. It is possible to create inflation via unwise spending on limited resources but the private sector is much more at fault for this than is the currency-issuing federal government. As long as money is deployed to purchase existing, or potential, resources in the private sector within limits of production there is no inflationary risk in that spending.

Given that money creation is not dependent upon "revenue" in any way (and in fact is the cause of said revenue being available to invest) the concept of credibility is entirely invalid as you implied it. You've mentioned the term "sovereign" in the context of the federal government's ability to create the currency but your further elaborations suggest that you don't understand the meaning in relation to a "sovereign" fiat currency.