Yes I know exactly what VMG means and have done for over 40 years !! My sailing experience is approaching its half century !
The question wasnt VMG down wind it was VMG upwind in 20knots and in resultant water conditions expected ith 20knots. ?
Yes we all know Formula can outpoint Slalom.
In 2O knots slalom boards approach 40 knots.
There`s a reason Defi is always on on slalom kit.On those days there VMG is probably better.?