I have a big ass bright programmable shift light on mine . Staring straight out at the road and you can still see it out of the corner of your eye so you can focus on riding and shift right when you want to, to stay in the meat of the power band. I dont use it for every day riding. (obviously since its programmed to light up right about 15,000 RPM) .I don't doubt that those numbers you posted are accurate, although I am interested to see the graphs and hear your explanation. What I do doubt though is that any non professional can hit those exact RPM's on a consistent basis and keep full focus on the road.
I go partly by engine sound while shifting with a quick glance at my tach. I'm not going to sit and watch my tach to make sure I hit the exact perfect RPM before shifting, while the scenery is whizzing by. I usually get it between 10.5 and 11K, which is close enough for government work as they say.