I have found that of the many ways to divert air with a windscreen or fairing, most usually create more turbulence than I like. That's what wears me out...buffeting. Truthfully, I'd rather have full direct wind than buffeting. The LeMans is a rare one in that, it's just right. I still get direct wind on the upper helmet, so there's no turbulence. The main body of the fairing carries away the rest. I'd recommend further experimenting with "lips" and the like. It doesn't take much to get a sweet spot. I had the MRA adjustable on my BMW and it was better when in the low to mid position, and terrible on full up. Try just a small length of tubing, split at the side, and push it on so it fits round the edge of the stock screen.
Noise-wise... If you use a modular helmet(?) it will be noisy.