[Minor49er]

This reminds me of a project I worked on that had an interface with draggable boxes just like this. The library that we used rendered the boxes as divs while the arrows were drawn as SVGs. Apparently there was a bug on Internet Explorer 11 where CSS transforms being applied to SVGs would cause the browser to slow to a crawl, or crash entirely if too many were happening at once.

To get around it, I switched the line drawing function for IE11 so that it would draw two divs that would extend from the middle of each box and touch corners in the middle (basically figure 4 in the article), then style them with a curved border on the appropriate side. While not as elegant as what's shown here, it was convincing enough that nobody noticed any visual difference between it and the regular version.