I'll reply for Sussed
After analysing more what happens.
It is the opposite.
My index and thumb are driving.
As they always rotate with the gripshift.
When doing 1 to 4 gears jump at a time.
The 3 other fingers barely move.
Then I take back the relaxed position.
For bigger gear jumps, I just keep the gripshift between the index and thumb.
Release the 3 fingers.
And roll it and hold to the desired position.
Without voluntary ratcheting.
May be a slow motion video, would help to make all this pseudo-science verified!