There’s a lot of dvhe DV P5 content out there. Unless Plex makes a change I don’t expect dvhe to work on Apple TVs. Apple expects dvh1.
Simply relabeling dvhe to dvh1 doesn’t work, because they should be muxed differently.
The straightforward solution for dvhe is to extract the raw streams and mux them with MP4Box to produce an Apple-compatible dvh1.
But that process is annoying when there are many streams. 
ffmpeg emits files with hvc1, which I think is incorrect behavior. But hvc1 is muxed similarly to dvh1 and can be easily relabeled with mp4dovi.
So a lazy, good-enough option seems to be:
ffmpeg -i input.mp4 -map 0 -c:a copy -c:v copy -bsf:v hevc_mp4toannexb -tag:v hvc1 -strict unofficial -movflags faststart output.mp4
mp4dovi -from hvc1 -to dvh1 output.mp4
Feedback and observations from others?
