Tried Fast & Furious - Hobbs & Shaw.
Using eac3to334 to extract both hevc video tracks
Using yusesope tool version .003 in "-mode 2" to combine the 2 hevc tracks.
Using dolby mp4muxer to create mp4 (profile 4) without audio.
Mp4 Mediainfo: HDR format Dolby Vision version 1.0 dvhe 04.00, EL+RPU / SMPTE ST 2094 App 4, version 1, HDR10+ Profile B compatible
On firestick 4K
Plex: TV triggers Dolby Vision but black screen
Emby: plays HDR10+ correctly
MXPlayer: Just black screen
Maybe I am doing something wrong?????????????
But I am convincing myself that I need a Shield 2019
Thanks a lot for your help.