Just to set expectations for other operating systems, my understanding is the 6.14 fix is a workaround and the underlying issue is a misconfigured minimum value in the display controller board firmware (panel?). The kernel fix overrides the firmware value. Is this correct?
Pretty much exactly that.
How to measure the improvement without professional instruments? Put a solar panel in front of the screen?
With your bare eyes. It is very noticable.
Or make a picture with your phone with different kernels.
What about those who have to use Windows for various purposes? Firmware update coming to address this?
No idea. I’m a Linux user/dev.
The latest statement from Framework is in this very thread. There is no software workaround for Windows since source is not open. You are totally reliant on a firmware fix from the hardware vendor.