I thought it would only take an hour, but I ended up spending a few hours adding that functionality for you. It will now save and load json maps and export a png of the map. The Fileinout extension broke, so i removed it for now in this version, which means it will only save in game makers allowed sandbox areas unless you're running the project in the editor. I added the project to the download page and tried to update the game example project Save and Load scripts which should work, but i didn't have time to test.