I've spent a lot of money trying to solve the buffeting problem but after one year of trial and error I've had it solved. It's not only the screen. There are some other things to do.
So, I started by changing to BMW touring screen, no joy. Then Puig with spoiler. Better but not solved. Then Givi. Again better but not solved. Then Wunderlich. This time much better but still some buffeting. Then I added MRA spoiler on top of it and it gave me some further improvement. As for the screens, that was it for me. 80% of the buffeting was solved but I still wanted to solve the remaining 20%. Next step was to add 20mm spacers (and longer bolts) to lower bolts that tilted the screen towards the rider. Big improvement but 10% of the buffeting was still there.
Those remaining 10% I solved just recently when one day I remembered to test the bike without OEM hand guards. The buffeting was completely gone, 100%. Ordered and installed Burkbusters and buffeting hasn't come back.
So, in my case, problem solved 100%.