Brightness adjustment BW screen

[jakejm79]

Does anyone know if the brightness adjustment actually changes the backlight level of these screens? My brief look over the driver board and the GUI of the controls make it seem that its a fixed backlight and the adjustment for contrast, brightness, etc just control the actual LC.
My plan is to dial in the settings and then remove the button board, but if turning down brightness does indeed reduce the backlight then they might say for the battery saving implications.