I find the responses to my question fascinating and thank all of you for your interest.
It would appear to me that the Bimini loop ( aka the Bimini twist loop knot) incorporates in its construction both twisting and furling--I will leave it to you to decide which component is most important, but in my current view-- THE BIMINI IS A FURLED KNOT!!!
I am still preoccupied as to how the loop component is built into the tippet. It is a very tight twist or furl and the length is about twice as long as the Bimini component. I do not think it is a cat's paw as in the offshore swivel knot. I am leaning more to it being a tight twist made in the bight and then somehow Orvis ties a Bimini to finish it off.
As to why I don't simply use a furled mono leader--believe it or not I frequently catch eels on a dry at night along with trout. The eels invariably wrap about the leader and an amazing amount of their slime is left on the leader. It is far more difficult to clean a furled leader as I discovered late one afternoon after a night spent fishing. I had replaced the leader during the night, but hadn't cleaned it. I smelled a pong emanating from my fly vest and discovered that it was coming from the furled leader. It took as long to clean this leader as it does to construct a new one.
I can hear what I think are the eels taking flies off the surface-it sounds louder than the browns but I can't really make the distinction. I cast to the sound in hopes of obtaining a good drift--it is too dark for me to actually see the rises. It is very exciting fishing.