Yes, I tend to miss the humor then I get lost with terminology; a smiley will help 🙂
As for the angle of the airflow hitting the reed, I don’t see how you can change that in either of the design alternatives (p-before-r or r-before-p). This is a benefit you get from BEING the valve.
As for the rubber and indirect pressure, I read that but I find it non durable as you count on a stretched rubber to maintain its sealing. I believe that this mechanism will break quite fast, which makes me go back to distinguishing between stopping the air from going-into or -out-of the chamber / tunnel.
Again, in the harmonica, you ARE the valve. Therefore you recreate the sealing yourself as you need.
Using mechanics for such task is very hard. For the possibly best scenario, I imagine myself a tunnel with a valve inside, where one side you have the small air chamber splitting into the tunnels, and on the other you have the reeds.
As for the sound manipulation, I’ll try to explain.
In order to make sound manipulations such as the examples detailed, you must do that after the air has passed the pads and the reeds (the order of things is negligible). Having the reeds last, the sound will go directly from the reeds (let’s say that you don’t need to protect these). Having the pads last, 90% of the sound will go through the pad. I believe that you missed that I wrote that on my original post on material test.
so either way you have a specific region where you can control the sound using different materials (such as wood, muter, etc.) just by having the cover of the instrument built for that, letting you access to the area.
I believe that in reeds-before-pads you have a “tube” of sound from the reed to the pad, just like a trumpet (or the closer relative, the Claviola); unlike the trumpet (and like the Claviola), you have a dedicated tube for each note. The fact that the reeds are berried inside the instrument doesn’t mean that the sound behaves like that.