I think some of the concepts in this doc are sound from a constitutional point of view. But from a background and intention point of view, it was pretty clear that the Founding Fathers felt very strongly about the separation. They only formally codified it in a very simple way in the 1st amendment and NOT the main part of the Constitution.

Why does this matter?

So that we should be familiar with what is actually written in the constitution and the bill of rights if we end up in a debate with MAGA crazies.