Correct. But you can write a Config, and host it online somewhere, like in your GitHub. From there, view the FIle, and click on Raw to see the full text file in your browser. Then copy and paste that URL into the Launcher's "Open URL", and it'll load up for you, and your testers.
In the future, when you are ready, you can just give me a link to your Config file, and I'll be able to add it in to the default.