Poor performance in IE11 with large number of items

If you try [this codepen](https://codepen.io/Neaox/pen/PPeXyy?editors=001) in chrome, edge or firefox the performance is good, however if you try it in IE11 it's a bit jerky when dragging. Is there anything that can be done about this?

Thanks.

Start by reproducing the linked CodePen in IE11 and comparing its dragging behavior with Chrome, Edge, and Firefox. Then trace the repository's drag implementation to find the source of the jerky performance. Done means the large-item example performs acceptably in IE11, with the relevant behavior verified across the browsers mentioned.

Written by the indexing model from the issue text.