I decided that I wanted to draw some boxes using the box drawing characters (https://en.wikipedia.org/wiki/Box-drawing_character) that Source Code Pro has to offer (this to be working is necessary for my intended application). Unluckily it looks like the box drawing characters "don't fit together" in the WOFF2 version of Source Code Pro, see the rendering of the following codepen:

http://codepen.io/nubok/pen/mPKMNw

I tested this in Google Chrome 49.0.2623.112 m and Mozilla Firefox 45.0.2 EME-free (here the artifacts are particularly marked). Note that Internet Explorer 11 does not support WOFF2 fonts.

In the WOFF version the rendering is correct in Mozilla Firefox and Internet Explorer 11. In Google Chrome there are still small artifacts even in the WOFF version of Source Code Pro. It is thus not clear whether this is a bug in Source Code Pro or Google Chrome.