Strada, this extension looks great and could work well.
Odin, the extension on my bike works well due to the spacing of the screen that allows for airflow to fill the gap between the rider and the screen, I do however also find the wind hitting me just below my helmet and this creates a buffeting sound that could damage your ears if you do not wear earplugs, I also think that to increase the height with +- 2cm will be better.
I find that I can also more freely turn my head on high speed [160 kph] with minimum effort; I have a peak on my helmet that has a great influence on high speed