You can use tools like the one you posted (or others like ghost, phantomjs or selenium) for your personal use (depending on the OS you're running) but it will be a pain in the ass (not to say impossible) to package and distribute your addon for others.
Another alternative is to create and host a webservice somewhere that runs one of those tools and that can be called from your python script as if it was an api (it won't probably work well if your addon has a lot of users).
Unfortunately, your best bet is to reverse the javascript code and port it to python, so your addon can resolve the final html code. In a distant future, with CEF probably incorporated (see:
http://esmasol.de/open-source/kodi-add-o...b-browser/) kodi might support html5 based addons and solve this issue in a different way.
Cheers