I've been making more improvements to my screen setup, mainly because I altered the Madstad position for riding 2up and had trouble finding the sweet spot again..
Went out over the weekend with the misses on and merely pushed the screen forward a little to counteract the attack angle change of the bike (with the rear depressed) and it worked great, really well actually. However I think the biggest difference was that I'd unclipped my Sat Nav holder from the bar I'd fitted above the clocks.
I think that by moving this big airflow restriction the screen can properly establish the bubble for us to sit in. We both noticed that even at an indicated 100 mph (real speed probably 90) it was relatively quiet.
I have now replaced my Sat Nav holder for a smaller phone holder and it'll be interesting to see if that proves to be better.