If you're have transcoding issues for any reason and want ffmpeg to transcode to dnxhr lb sq hq, etc
Download FFMPEG and AnotherGui and create a preset with:
-i "<FullSourceFileName>" -c:v dnxhd -profile:v dnxhr_sq "<OutputPath><OutputFileName>.mov"
You can switch the quality by changing _sq to whatever you want. Don't change anything else.
You can later consolidate these videos in Media Composer.
Sometimes one needs to work at the same time, avid background transcoding can be slow, MC can have errors, Or MC isn't using all the cores due to the quicktime dependancy. This is good to have in the arsenal just in case.