Cusco
Its a form of drag and we are talking about energy management so I can see occasions when removing the drag part of the flap stages could be useful.
In an engine failure full flap should be taken when assured of landing but pilots do get it wrong and I could see that removing that drag could extend the glide range
I know in my Seneca Five days I rarely used full flap for landing unless the runway /strip was very short especially in a twin you want as little drag configured to land as possible in the event of an engine failure or even a go around.
Pace