ACES 1.3 Reference Gamut Compression Matchbox Shader.
You now have access to a new ACESRefGamutCompression Matchbox shader. This shader fixes an issue with very saturated colours (police car lights, neon signs, etc.) in source camera footage that clips in an unpleasant way in the ACES Output Transforms.
The input to the shader must be either in ACEScg or ACEScct colour space. If necessary, use the Colour Mgmt node to convert to one of these two spaces.
Unlike the previous ACES "Blue-light-fix" algorithm, only colours that fall near or beyond the AP1 gamut boundary are adjusted. For more information, see this ACES Central post.