Curves are applied unequally in HDR and SDR mode, unlike other tools

When HDR is toggled on and off, clipped highlights become visible, nothing else changes... unless curves have been edited with one of the 4 preset variables. No other tools or sliders have this effect. Once curves are used, HDR SDR equivalence gets broken. This looks like a bug becasue no other tools behave like this, and it can also be very inconvenient.

To handle HDR and SDR consistently curves should not reuse the 4 points/variables "Highlights" "Lights" "Darks" and "Shadows", but should instead add 4 more variables that control the HDR half of the curve. This way controllable resolution of the curve tool will also not be cut in half by switching to HDR mode.

Custom point curve mode of this tool already works like that, and does not have any of the issues described.

Currenrtly workaround for this bug is to always be in HDR and use "Preview for SDR Display" with Contrast -100, Clarity -100, and Whites +100, instead of switching to SDR mode.