Fitted a laminar lip yesterday and let the glue pads set overnight. I tried a variety of heights with tape as suggested by the instructions, but found this to be a waste of time. Using tape, the lip is not held securely in place, so at any reasonable speed the buffeting gets worse because of the screen movement. In the end I settled for the lip in a high position (higher than the position shown is post 4 here), with the top glue pad fairly close to the top of the standard GS screen.
I am 6'4" with the standard seat on high position. With the GS screen I got a lot of noise / turbulence straight at the visor, really noticable at 60+ mph. Top screen position was always best, lower positions seemed to increase the noise but not lower the impact point on the helmet much.
With the laminar lip fitted, the noise / turbulence is definitely better with the screen set in a trial position 1 notch below top. It seems logical that with the extra kick up on the top edge of the lip, a slightly flatter screen position would work better. There is still some noise but much improved protection from the air blast.
I will try a few more settings and see how it goes over the next couple of weeks. I might try tobinators to let a bit more air under the screen to quieten things down a bit if it is still bothering me, and these might also raise the screen enough to run it in a slightly flatter position. Another option is the Saeng edging which might also clean up the airflow a bit.