In the book This Time Is Different, Reinhart and Rogoff take a more expansive view of default. So do I. To them/me, massive inflation is a type of default. Any means of paying off a debt burden by handing off something less valuable than what was received, plus interest, is a form of default.
Yes, the Zimbabwe option is available. Print money with abandon, issue debts with abandon in your own currency. Use what you get from that to finance your budget deficit. That has been done, but it is a form of default.
I give no credibility to those who say a sovereign nation can always issue more debt in their own currency, particularly when there are large voting blocs in society that will oppose inflation, or the fear of higher taxes from additional indebtedness.