so Plex is ffmpeg based? this would mean it will eventually make it's way to the app anyway. I haven't found any open issue tracker, maybe we should gang up and start posting and sending emails?
I've also tried your method of creating a single layer DV with Atmos->lpcm sound, but I lost the central channel somewhere in the process and I can't hear voices anymore. trying it out on Last Jedi bluray and testing the mp4 file out in VLC, media info says: Codec: PCM S24 BE (in24), Channels: 3F2M2R/LFE. any ideas on what might have gone wrong?