I run https://blog.jeaye.com/ on Github Pages, but I manually build with Jekyll locally, with a publish script, and then force push the built site + assets to the gh-pages branch. This allows me to use all sorts of Jekyll plugins which Github won't whitelist. I'm currently writing a post detailing how all of this works, for anyone interested.
Yes please. I need to support localisation on a site I maintain, and for that will need one (or more) plugins that github don't support so would be interested in your setup.