This is an interesting question. According
to Dennis Connor, the answer is as far aft
as possible.

I like your answer though. Downwind
reaching could mean as nearly as high as
a beam reach. Which would clearly
require weight on the rail.

1 point for you Peter

Weight forward in lighter air makes sense
to reduce wetted surface.

I like to study the boat's wake and the
feel on the helm as I move people around.

"Peter S/Y Anicula" wrote

Downwind: in front on some boats, aft on some.
Reaching on the rail.
So almost any combination is possible.

Peter S/Y Anicula

"Bart Senior"
Where do you want your crew to improve
downwind reaching speed and control for
most sailboats? [1 pt]