It’s a very broken system and a huge dollar maker for anyone who has the time and creativity to make a solid workflow. But, a workflow that I have used and works… I build my look in LR5 (works in 4) on a photograph, or simply apply a vsco filter to an image. I then take the sharpening and some contrast out, adjust things suitably for video. Then picture instrument has taken a swing with creatinf an application that converts jpg’s color profiles into a .cube file. I then use a program like lut utility or pixel film’s lut loader to upload the cube file and access it in fcpx. It sounds like a lot but it’s a pretty decent workflow. I put the url for the picture instrument lut converter down below. Let me know how it turns out or if you have any questions.
I’m also responding on my iPhone and generally don’t re-read, so if this is gibberish and filled with terrible grammar, sorry. Best.
https://www.picture-instruments.com/products/index.php?id=4