Quick confirmation of Storyline limitation

Hi folks, 

I had a quick query I was hoping you could help with. I'm trying to create a scrolling effect as students go from one point to the next that have been mapped onto a slider. So let's say students drag the slider down to point 1, element 1 moves down into the screen, students drag down to point 2, element 1 moves down off screen and element 2 moves down into screen, and so on.

The problem I'm running into is that while the animation with the motion path works right in one direction, it doesn't switch directions when students come back to point 1 from point 2 (in which case the direction of the motion should reverse for directional consistency with the slider, so elements should move up not down).

Is this a limitation of Storyline? I believe so, but I'd appreciate a quick confirmation.

Thank you!