Kuntk;
I think you're absolutely correct when you mention that " the sliders increase friction by speed regardless of gear size in the motor drive " . The other factors you mention also affect its functioning, however to a much, much lesser extent.
An interesting experiment is to, while applying a little bit of pressure on the top of the screen simulating the wind effect, to try to turn the adjusting knob to either lower or raise the screen. It soon becomes quite obvious that as pressure backward increases it becomes ever harder to either raise or lower the screen up to the point of becoming impossible to move the screen without braking the bike's original mechanism.
Once you remove the pressure it becomes easy to move the screen either up or down.
Corroborating on your original comment, the negative effects of flexing back the screen is the exponential increase of friction on the two bearings that should slide on their tubes, making next to impossible to move the screen uo or down. As the experiment above shows, irrelevant if the applied force to raise or lower the screen is manual or motorized, the system will not work at speeds above some 60 or 70 Km/h on the GSA and, having a smaller area windshield, at a bit higher speeds on the GS. Again I want to reinforce that this is due the flexing of the screen and its corresponding ever higher friction on the sliders.
On the instructional installing video, the up and down switch set is shown being mounted on the bike's right hand side. I plan to mount mine on the left hand side as this will allow me to use my right hand to put pressure forward on the windshield counteracting the backwards movement of the screen due to wind pressure. I believe that this way, I will be able to electrically either raise or lower the screen even at higher speeds. In fact, this is one of the reasons I've purchased this set as presently it is too difficult ( and dangerous ) to take both hands off the bars, one to turn the knob and the other to pressure forward the windshield, to adjust its height; its easier to slow down the bike...
I will report the results of these experiments as soon as I receive, install and test the system.
Andre