I realize that the system used to configure keyboard and joystick is not entirely practical, but it is the simplest in terms of programming.
Maybe one day I'll program a more complex interface that allows you to configure keyboard and joystick separately, and that allows you to configure only the buttons you need, but I'm not sure it's worth it, and anyway at the moment I have other priorities.
And to be honest, I think that once you decide which keys to use and get used to them, you won't need any configuration anymore.