Polar diagram for Mosquito?

Robert Ehrlich wrote:
"Lars P. Hansen" wrote:

The original flight manual has the usual single polar curve, based on the
glider being flown at optimum flap setting for any speed.


One may wonder where this kind of beautiful continuous polar comes from,
except if the glider has a continously movable flap lever. With the
usual disposition of a small number of discrete settings, the polar
should at least exhibit a kink when the setting changes.

Marketing department?