I do it a bit different.
After ripping and remuxing to a mkv, I use ffmpeg to convert the x265 .mkv to ProRes4444.
In Resolve I’ll then typically use a tonemapping LUT I created with DisplayCAL or another tonemapping LUT.
And finally still in Resolve I’ll do my final grade/edit.
Nice! That sounds like it would work really well too. Similar ideas. I like the idea of skipping a step and just going straight to ProRes in FFmpeg; however, I haven’t done that myself because FFmpeg’s ProRes implementation is unlicensed, and I’ve actually noticed a slight color shift with it. Maybe the issues have been fixed since I played around with it a couple of years back, and if so that would be awesome. That’s also a great way to get it into ProRes if you’re on Windows! Great thinking!