I have that one in my patent application but i did not build a prototype yet because i don't have access to a plane with control stick. It even has 2 axis.
It is already portable. So as long as i don't do something to it to become non-portable, it should stay the same. Like 1lb frame, 1.5lb counterweight, 0.5lb for the box. I'm working on making the motor part of the counterweight by making it sit on the slider.
This device is not intended to be used to fly maneuvers nor aerobatics. Solely for cross country, where you routinely bank no more than 3 degrees while tracking your flight plan. Most of the time the waypoints are almost aligned so you usually make 10 degrees or less of turning.
To entertain your discussion, it is a combination of gravity and centrifugal forces that pull the counterweight. Therefore, the system will retain some efficiency even in a 90 degree bank due to the heavy g loads that would amplify the 2lbs weight