I thought Dan’s whole point was to employ the KISS principle. The yellow tape goes on your minimum manoeuvre speed which happens to be 1.3Vso for a visual reminder of DONT MANOURVE BELOW THIS SPEED, to prevent us over thinking this thing and bending our airplane/selves.
Flightchops channel has an episode on YouTube with Dan explaining this.
I did manoeuvre once below a safe speed, and by some miracle did not kill myself and daughter, if I had marked a speed and knew don’t let that needle go past the line, it very likely would not have happened. I did seek remedial training before next flight where instructor and myself came up with a number that you don’t turn or fly below. It has worked ever since. I will be taping my ASI when I go to airfield next.