Facing difficulty in adjusting brightness for Spyder screen calibration on macOS 26

Before Mac OS 26, setting a particular screen brightness was easy. In previous OSes, one could press the F1/F2 buttons to adjust screen brightness. For my tastes and setup for Spyder screen calibration, I set Brightness to 50% (the brightness scale is not marked in percentages, so I set to the middle graduation). Calibration was easily repeatable.

In Mac OS 26, the F1/F2 Brightness control appears in the upper-right corner (cannot be repositioned on the screen, by the way), has no graduations, just a solid bar, making the setting to 50% impossible.

The brightness slider also doesn't stay on the screen long enough to make a good eyeball judgement of center/50%. Consequently, I have not been able to record attempts to set brightness.

In Settings>Displays, the Brightness control is static (stays on the screen), but does not have graduations, and it therefore requires setting 50% by eyeball.

Is there a way to be more exact in setting brightness, or would it take a coding change?

[Re-Titled by Moderator]

Original Title: mac os 26 changed the way exact screen brightness is set on mac air making it difficult to calibrate