Pressure change in a closed system is a result of flow rate, density of a liquid, and the diameter of the pipe, if we can change the pipe diameter we can affect the pressure (this is science). I do not believe your analysis of engorgement, when the blood becomes trapped that is your erectile state it is not a precondition to an even larger erection. I believe the valves under normal (relaxed) circumstances will allow the inlet of blood until the resistance of the cylinder will nolonger expand under the existing erectile pressure. This is why we can have muted erections, in situations that would include a full bladder or extreme arousal the valves can shutdown prematurely resulting in a smaller than normal erection. These conditions result in tension and an induced rigidity that screws up the ideal flowmetrics, everyone knows what tension can do to a golf swing.
I disagree. It would help to persuade me if you could provide some citations.
WHile you are correct that pressure CHANGE is a function of flow rate, pressure itself is not. Take an ordinary example. High pressure bicycle tires use narrower nozzles than low pressure tires. THe flow rate is lower, even though the pressure is higher. The two concepts are separate.
As for the mechanics of erection, this is very well understood and documented on this site. My time is short, so I can’t do the searching for you. But I suggest you look around and read what others have said (especially those citing reputabe sources). Then tell me whether you still disagree.
Enter your measurements in the PE Database.