Has this test been done with anonymized frames? I rode a friend's bike today that i built for him. It's basically my exact spec, but with a different frame. The fit and coordinates are a bit different, so i'm more comfortable on my bike because it fits me better, but i really dont think i can tell them apart while riding.
There's so much vested interest in maintaining the mystique around high end frames, i really feel that it's largely BS. Carbon frames aren't spaceships.
I'm unaware of anyone thats ridden a real sl8 back to back with a "clone", let alone blind. I don't doubt that there are layup differences between the two, whether they make a difference who knows. There is a fair amount of research that the big brands do on various layups etc., how much of that is an actual factor in real world ridefeel is another matter entirely.
As far as the pricing comments go, its somewhat opaque as mine increased by a couple hundred bucks between initial quote and final quote due to "an error" whatever that means, and i didn't ask for an item by item breakdown. My build was actually around the same price as the 105 build in this thread, but that build had lighter wheels, so i don't really know. I was a little disappointed that tantan couldn't source a Magene pm to swap out for their crank, even if I had to pay full price for the Magene. No powermeter options apparently...didn't ask about shimano's as theirs have such a terrible reputation.