Sorry if this has been suggested before. I'm around 5'11" and I have no problems with the stock screen whether I'm wearing a full face or a MX lid.
But a friend of mine who is probably around 5'9" and wears the XD lid was having problems. Another BMW owning friend lent him I believe it's made by Touratech, wind deflector that clamps on to the GS windscreen. Problem solved.