I’m not sure this is the right place for this since I’m running Windows 11 on the FW16. If someone knows where this idea belongs, please let me know,
I’ve found that lowering the brightness in the AMD Adrenaline software helps a little with the screen brightness. Unfortunately it doesn’t directly lower the backlight, but it does a better job than some 3rd party software I’ve tried.
The setting is under Gaming > Display, switch Custom Color to ON, then lower the brightness slider.