[robchalmers]

the long vertical edge below the chord reduces the spill round from the high pressure top surface, they are so long it make me wonder if he's trying to cut ambient pull-in, nee ground effecting the front chord.

As for the plate above the chord, I guessing it for flow reduction. at 315+ the frontal area and normal spill plate sides mixed with Hi speed laminar flow above the chord would box in the air effectively creating a parachute effect. At those higher speed the lower surface can generate a lot through a diffuser effect so you don't need the air on the top, so I'm guessing they're bleeding it out at the sides.

just my idea