Hi Mike,
I have to respectfully disagree with you about the pins.
If they were inserted at 90degrees with the belly they would be, as you say, "doing nothing".
The bamboo pins are inserted at an angle to the belly or "skewed" if you like, back towards the centre of the bow in to the belly wood thru the main lamination of the riser. Having them on this angle, increases resistance on that main lamination of lift, and in my opinion, makes the lamination glue line stronger.
Since I have been doing this, I have not had one riser pop or fail.
Along with longer fades, careful gluing, multi laminated risers and careful tillering with a rigid or static riser in mind, you can get away with having a thinner belly wood.
I have not included a power lam in my builds before, I take it they make the riser section more rigid? If that is the case, they have some merit and will have to consider including them to my builds, especially as I don't have the luxury of having thick belly woods all the time.
Mick.