Section 12.1 "System Screen" of the "StudioLive_Series_III_OwnersManual_V6_EN_10062019" might be helpful here: "4. LED Brightness. Gives you a range of brightness settings for the LEDs. Choose Low, Mid, or High brightness for each" and "5. Backlight Brightness. Sets the brightness for the displays on your StudioLive (scribble-strip and touch). Choose between Low of High."
There is not really a danger of a burn-in of LEDs, scribble strips and touchscreen.