That isn't a reason to not touch it at all, nor did it get any more complicated than it was first
.
While the blur is just a thing I added because I could (and I honestly doubt it's causing the problem), the current selector-based loading overlay is way simpler than the old technique. This also reduces complexity to create those visuals and amount of data sent (as it's all css).
In fact, there's a huge chance that if you try it in another browser it'll work just fine as freezing the whole browser is clearly a bug in that software. Who knows even IE performs better
.
Or some plugin in your browser messes it all up, or some configuration of your browser does (hardware accelerated rendering?)...
If anyone else has this problem, though, be sure to yell here.