Okay, all fixed! You may need to restart Steam to ensure you have the latest version. Please let me know if that works for you!
What was wrong is the Tutorial was hardcoded to just using whatever controller was assigned to the first player. The issue is that occasionally the controller you want to use is not tied to the first player. Now MageQuit automatically detects the active controller based on input and will even switch off mouse and keyboard controls to controller if you clicked tutorial instead of using A. Basically, it's bulletproof now!
Thanks for letting me know of your issue :)
Also, not gonna lie, I'm having some serious controller-envy right now haha.
Brett