For example to which key?
When you get back to keyboard mapping. How about making 2 presets, we can switch between with fn+space. 1 for keyboard and mouse only, and 1 for joystick and mouse only. That way we can set joystick like we want with out messing with the keyboard.. Then when in-game, and your playing a game with joystick, if you suddenly need keyboard, it takes 0.5 seconds to switch over to keyboard preset with fn+space, and type what you need, and then go back to joystick again.