Since key names like "0" and "9" would conflict with keycodes (and generic actions as currently implemented for this issue), these names likely need to be prefixed.
Possible examples:
joy1hat = key_up, key_down, key_left, key_right joy1button1 = key_A joy1button2 = key_S joy1button3 = key_3 joy1button4 = key_KP5