I can see your point Henning
Another general rule would be to use the turbulator towards the front if you want to keep the boundry layer at high lift coef. eg high angle of attack (with a penalty increased drag on cruise speed)
or place it further back to work better at low lift coef. (straight and level at cruise speed) with less drag but no effect at high AOA.
I will place mine a bit further back and report the results..
Nice...!
Elias