Obviously if a manufacturer could prove their high end cable to be audibly superior to others then you can bet one or more of the hundreds of manufacturers would be offering demonstrations - quickest way to make millions of $ so it is not like there is no incentive to prove the superiority of a product.
+1
And, obviously if a forum member could demonstrate they could hear a difference with said cable oriented one way or the other, they would have taken me up on the offer I made herein this thread on 03-10-2018 6:55pm.