I forgot to say I work only with uncompressed files (x264 gave some trouble, uncompressed works perfect). I convert them using virtualdub, then save as quicktime .mov. The project should look for the source file I worked with. I’m assuming you’re already bypassed this issue.
When rendered, I then use a brief avisynth script + megui + x264. With mkvtoolnix you can load the original 4K77 and simply replace the video with the regraded one.
BTW, in this 1080p regrade I worked a bit with the frames to remove reel change marks. So, no more cigarette burns in this regrade 😃