Digital Light & Color

It looks like Settings/Clipped Pixels/Shadow Threshold for both colours is always taken as zero irrespective of the value entered. Highlight threshold seems fine.

Not seeing this here - how are you testing? I tried it with a step wedge.

Can you try it on this image? The shadow threshold is set to 5.

Not sure if the patches are just mislabeled or if JPEG compression is messing with them, but the labels do not correspond to the actual readings from the readout tool.

I think I know why: you use AdobeRGB working colour profile and you saved and reopened the file, automatically converting it to the working colour space. It's the straight line at the beginning of sRGB Gamma curve. Try not converting it or turning the Colour management off.

It turns out what the clipping indicators are showing is based on the image being displayed on the monitor and not on the underlying image data. The monitor data has been converted to the monitor color space so it clips slightly differently from the image. I'm not sure how easy this will be to change, or even if it should be changed, but I'll take a look.

Cheers!

A related question: does it mean that the Readout Tool still shows the image data?

Yes, the readout tool should be OK.

For the next release, I fixed the highlight and shadow clipping to reference the zoomed underlying image instead of the color managed version.