There are a couple of ways to avoid buffeting caused by the windshield. One is to have a fairly tall shield, where you can just look over it and the air stream hits the top of your helmet, not your ears.
The second is to have a fairly short windscreen where the helmet, head and ears are all out in the clean air stream, again no buffeting. With this arrangement, the air which just clears the windshield hits your chest, so you have to lean forward more at speed to balance the force.
The miserable stock windshield has a shape and height that looks good in a show room, but is awful for buffeting when actually riding. I think that cursed flip top makes things worse.