When you're right you're right.
I did crazy things when I was young and stupid 10-15 years ago (I'm 68 now) when I removed the asbestos from the the entire exhaust:
- I did add a flange from a plumbing supply place
- So the exhaust pipe IS screwed into the flange not the manifold
- I did gunk it up with high temp gasket sealer
- I put a hose clamp on to hold the gasket sealer stuff in place until it dried
- I never took the hose clamp off. (so no that clamp was not intended to have any structural value
See picture