I am intrigued by all the talk about these stoppers! It is indeed crazy to think that a piece of plastic can make that difference - and the new crown with a hole in it - the head apparently becomes some kind of resonance chamber 
Cool that Robert Bigio admits himself that he does not know how it works, but that players confirm that it works.
When taking out the cork of my brand new Bb flute, a bit of cork chipped off. I used that as an excuse to order a crown and stopper from Bigio 
He wrote he never made one for a wooden Bb before, and welcomed the new experience.
I’ll post more when it has arrived.
Cheers,
Jeroen