“ You certainly don’t want them to be inverse of any display transform, they need to represent plausible values either in the scene, i.e. Scene Referred or for the shader parameters they are driving. Having them bound to a particular display means that as soon as you change your display, your textures will not work anymore.”
I’d like to return to this point to hopefully understand it better. My understanding is that the display transform is basically doing two things: converting from linear to the display (Say sRGB) and a tone curve. If I have a texture map in sRGB space and I invert sRGB on it as well as inverting the tone curve then it has been made linear. The only issue is values above one which can be solved by an additional matrix like the dt in spi-VFX. But texture has been properly linearized now and has no illegal values.
When that linearized texture is rendered and a different display transform is used to take it from linear to say P3, I would expect that to work just fine because it’s going from linear. It does in fact work fine with spi-VFX