It's a Cocoa app running on macOS. Current OS is Ventura, and Xcode 15

Thank you, that's working. One more question: in your example you explicitly set Enable-Private-Data for the app log category. Is it possible to enable it for all categories without having to list them all explicitly? thanks again

Ah, of course. The full name of Context was BrokenView<Something>.Context and in the place it was being used in the Preview it couldn't work out what the generic Something was. Thank you. I was bashing my head against it for ages

Thinking that maybe I should be observing to NSTextLayoutManager.usageBoundsForTextContainer for changes through KVO, but it never seems to change so maybe not?