Slow when drag 2000 elements

[PertapaCode]

https://jsfiddle.net/santos91/2jjg6te3/5/

In this example, scroll to the bottom of the page (just to set the right size for the scrollbar) after, if you drag the scrollbar thumb, the list becomes slow.

This is related to the way scrollerjs handle to go from one position to another right?

Probably there is a loop to iterate all the elements from position A to position B, but when we have a big list, I think this approach is not the best one.

There is a simple way to fix this, if not, what the complicated way involves?