Thank you for looking into the other sites.
I blew up the distance - time curve (with of course loss of resolution). How much of the ejecta (length of shot and wad) has entered the cone at .0003? How long does it take for the "legs" of many wads to collapse? Why is the pressure falling at .0005 with ejecta still in the cone? What does overcoming inertia vs. friction vs. some degree of constriction on the ejecta upon entering the cone have to do with the pressure curve? How much constriction IS there from case mouth to cone with modern shotcup loads?
I said nothing about crimps, or wad seating pressure, or plastic vs. fibre wads, the wad design, or internal ballistics of the shotshell.
Neither one of us KNOW the effect of the ejecta entering the forcing cone, nor can we answer (with numbers) the OP's question. Do I have that correct?
