Most people use DCP creator that handles all that and mostly do not have to use separate lut.
Mostly displays are not able to reproduce accurate p3 and if you have exact calibrated
709 then you get accurate dpc after conversion.
—
Margus
https://iconstudios.eu
https://vimeo.com/iconstudioseu/videos
DaVinci 9, OSX 10.7.4
MacPro 5.1 2×2,93 24GB
GTX 470 / Quadro 4000
Multibridge 2 Pro