Nice find Jim! Figures Rio would have something within their incredible range of flyline products for the avid anglers of the world.
That design would prove out the back taper theory, and I will contact Rio about it.
However I foresee a couple of possible things to overcome. It would have to be made longer to make a difference since the length of that line (100ft, 105ft after replacing the Rio tip with a shooting head) is already easily reached without shooting any line into the back-cast. If it in fact allowed for a back-shoot then it would add distance, requiring more length. In short it is shorter than the casts we are already reaching without shooting into the backcast.
Also without a color change there would be no visual queue to tell the caster what is going on in the backcast, i.e. when the max overhang has been reached.
Yet the back taper is there and would prove out the hinge reduction theory plus it already has a loop for the shooting head. Maybe a spliced extension on the other end of the running line to make it total 150ft long, which is plenty to worry about in even the biggest stripping baskets.
Actively working on a two-hander basket for very long running lines. First prototypes look pretty freaky but I hope they will deliver. Fingers are crossed for field testing at boneclave.
Thanks for your suggestion Jim.