None of which addresses the fact that the loans that are going heavily bad on the FHA side are the 0 down (through seller funded DPA) loans to folks with sub 620 scores – which simply aren’t available any longer.

That is not true delinquencies are still trending up even with loans originated after the seller funded down payment was stopped. Probably because of two reasons:

1: Unemployment
2: Huge shift in origination towards low down loans. Which trajectory is still moving up. Don’t discount “ambitious” mortgage originators either!!

The theoretical and real world are much different places.