My highest priority for a windshield is good vision, and that means the top must be just below my eyes to blow bugs over my faceshield. The only one I know of that qualifies is the MRA CustomShield, and it needs significant modifications to work on my 790 Duke.
The CustomShield worked well with the leaned forward position of my CBR600RR. It was exactly the right height and the bottom edge cleared the windscreen of the bike, and the forward lean put my head close to the shield where there was minimal turbulence.
As I turned 70 I decided I no longer wanted to cope with the forward lean of the CBR and bought the Duke for a more comfortable seating position while retaining much of the excellent light weight handling of the CBR. However, there were two problems. The CustomShield set at maximum height was too low, and the limitations of the mounting system put it far enough away that even if I ducked down to look just over it I still got a fair bit of turbulence at my helmet.
I solved the first one by cutting the mounting rods in half and glueing them into stainless pipes with the right ID, giving me the six inch rise I needed. But this caused another problem: The extra leverage meant the plastic clamps that attach the rods to the handlebars couldn't be tightened enough to keep the windshield from blowing back (even with pool cue chalk under the clamps, although that helped a lot). I solved that by getting a second mounting kit and using the stock length rods attached to the handlebar near the controls to support the longer rods that attached between the mounts for the handlebar.
I worked on the turbulence problem by adding an MRA X-Creen (a clamp-on variable windshield spoiler blade). This helped a lot but was far from ideal. I got a cheap wider blade of similar design from Amazon and it solved the problem completely. Instead of discarding the X-Creen I mounted it upside down on the bottom of the windshield to partially fill the gap between the windshield and the instrument panel.
I'm sure the haters are going to complain that this looks really ugly, and I agree. However, I think the Duke is so ugly to start with that nothing I've done to it can make it look any worse. I'm one of those superior people who think function is far more important than appearance.