[Warner306]

I would start by creating a single DCI-P3 3D LUT to handle both HDR and SDR sources. A single 3D LUT should be able to map BT.709 SDR sources within the DCI-P3 color space and could also handle BT.2020 HDR sources.

Or, you could create a BT.709 and DCI-P3 3D LUT for SDR and HDR sources.

I don't think you need any profile rules. madVR is supposed to select the closest color gamut that matches the source.