Before opening the issue, have you...?
Is your feature request related to a problem? Please describe
My external monitor is less bright than my Mac's built-in display. As a result, under normal settings, the brightness slider on the external monitor appears longer (i.e., set to a higher level) to match the perceived brightness.
However, when ambient light changes trigger automatic brightness adjustment—especially when the external monitor reaches its maximum brightness and then scales back—the brightness sliders often end up aligned. At that point, the external monitor actually appears slightly dimmer.
Describe the solution you'd like
Is it possible to remember the user's preferred relative brightness relationship between the displays and try to maintain it?
Describe alternatives you've considered
none
Anything else?
No response