I'm not planning to force anyone into using GitHub to be able to contribute to the project, but I do believe this is an excellent example of the benefits of having version control and working with branches. You have a branch in which you're working through something substantial that will take some time like the exit numbers. If you want to make an unrelated fix that you want to get in immediately, just switch back to the master branch, make that change and issue the pull request, and merge that commit into your branch to carry on.
Again, I don't plan to force it on anyone, but any time spent learning to work with version control pays back many times over down the road.