What's the status of Dolby Vision + Atmos on Plex? (re: LG WebOS, Nvidia Shield, Apple TV)

Has anyone figured out what DV combinations work on the WebOS plex player?

For example, I have this file:

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L5@Main
HDR format                               : Dolby Vision, Version 1.0, dvhe.05.06, BL+RPU
Codec ID                                 : V_MPEGH/ISO/HEVC

It will not activate DV on the WebOS plex player despite being layer 5. It works on the shield however connected to the LG.

On the other hand I have this DV file which works fine both on WebOS Plex and shield Plex:

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L5.1@Main
HDR format                               : Dolby Vision, Version 1.0, dvhe.05.09, BL+RPU
Codec ID                                 : dvhe
Codec ID/Info                            : High Efficiency Video Coding with Dolby Vision

I guess plex is at the whims of the quirks of the webos player. Is there any source of information about what exactly it can support and how to modify mkvs so it will work with DV? Thanks!