I know you are looking for Greg’s response. After reading your initial post, I thought BE to be something to look into. I am still turning my head for “get a great range quick” schemes. BEWARE of get rich quick schemes 🙂

It seems from what I read that it is a lip rolling-in technique as you ascend. Is this correct? That seems to be the essence of it.

As far as the aperture is concerned, from my understanding that is just one important aspect of shape and that the tongue and the jaw is the other when ascending as well as a slight pivot of the horn.

Pivot of the horn is different for everyone and ideally is kept to a minimum.

The other idea about the aperture must be set before applying air, may have some value. It has been my experience that the aperture also responds to the air.

If this system causes you to clamp the lips, then I think it will be inefficient. The developer of BE may not intend for disciples to do this, but it might be an unintended consequence for many BE followers. That is what I have experienced with students

Can you describe more of the techniques?