On stereo or multi-track playback the time index slider is very hard to use —[]———- the touch screen area is so small for this. You can’t get it back to near beginning because it is too close to the touch screen edge. It is also very hard to move it to a time index with any precision.
So out of chance I selected the time index slider and want to see if the screen rotary knob would control it. But it did not. This would be a great feature like you have used elsewhere in the UI. If a screen object has been selected then the screen rotary knob can control it. In this case move the time index slider left/right.