not FORCE, but it IS joystick feedback:
SDL_JoystickGetScreen (# of screen)
SDL_JoystickGetScreenID (label of the screen)
SDL_JoystickGetScreenByID (get by ID label)
The screen data type probably should be a SDL “screen” or off
screen bitmap. Not used outside a dreamcast; HOWEVER, someday
buttons will be able to display graphics on them, in which case, you
have a lot of icon-size screens you can put controls, or even simple
animations. e-paper/OLED is coming. These are input-related devices,
and secondary display devices, so they should be treated like a
touchscreen/stylus with display—I bet Wacom does it! ; joystick
related displays / buttons.
Maybe something for joystick lights would be useful, but I’m not sure
how people would use that. The screen thing will probably happen,
lights will not seem worth it at that point.