The top tracer info box indicates spin dot moved a %age above centre or a %age below centre, it doesn't mention topspin or backspin.
If you are in 40-50% rough and put full back spin on the ball (move the dot to the very bottom of the ball), hit the ball, then view the Top Tracer you will find the spin value is not 100%, it is less. It appears to me the spin value is not how far you moved the dot from center but how much BS is applied. The backwards arrow is also another indicator. The arrow points forward for top spin. I realize it doesn't specifically say "top" or "back" but...
This along with the tutorial and also from a programming point of view, it would be very strange to program 25% forward, then convert it to be a percentage of backspin. I respect your opinion and I understand your point about the wedges, but I guess I am just going to have to respectfully disagree.