Mind telling us how the proxy works or putting up some source code(couldn't find the proxy source on github)? I am also lazy and didn't read the whole script source, i bet it could be recreated with some effort. uft :D
For the HTML, it just checks a simple charset check and does the same as for images.
There are plenty of examples of the script embedded on the page though, and you can always download a copy from github and try it on your own page meanwhile.
I'm working on a browsers addon to help with remote support, mostly my mom. Thought about VNC or the like, but that's a bit of an over kill when I can just run JS in the browser.
This works great in letting me see wth she is talking about when some website is broken. This is my play ground for it, bragcollege.com. If you want to log in and play around let me know.