I’m trying to add this functionality and a few other things but running into a few problems. The plugin is very poorly documented and the code is a bit of a mess. Still working on it.
W3 Total Cache allows you to specify your hostnames but it looks like the first one is limited to CSS only so I’m not sure if you remove them all it will still serve images from the CDN.
What is hard to maintain about it? Just curious as I’m using it and haven’t touched it for a couple of months. Not sure if I’m not doing something I should be doing.