I think that the date for the credit crunch has to be revised again.
https://www.bloomberg.com/news/articles/2021-06-17/yield-on-30-year-treasuries-tumbles-as-curve-flattening-picks-up
Charts you are right,
The fiscal stimulus moved the IS curve to the right, a movement that can be offset by raising taxes, if they want. Actually, what the MMT people advocate is for central banks to fix the interest rate at a low level and then move the IS curve to the right or left as need be.
