Also, your blog is fantastic, I’m always happy when there’s a new post =)
Thank you, I’m glad you like it!
I feel like in SDR mode, the OLED is pushing brighter images. I almost feel like it’s underselling the capabilities at 270, but does so to give pixels a rest every now and then, in the hope that the bright spots don’t stay stationary on the screen. It’s a wild guess, I have no idea.
It’s certainly possible, displays do whacky stuff sometimes. For example, if the maximum brightness in the HDR metadata matches exactly what the display says would be ideal to use, my (LCD!) HDR monitor dims down a lot, making everything far, far less bright than it actually should be.
KWin has a workaround for that, but it might be that your display does the same thing with the reported average brightness.