That handles 4k HDR and also True HD and DTS:X
It runs kodi, so for plex you need to install the plex for kodi addon
Unfortunately plex have not updated the plex for kodi add on since may and im not sure how well it works.
There is another option though called Plex Kodi Connect
Also You don’t have to buy a Vero 4k if you are prepared to do a bit more work and messing around.
You can buy any S905x, s905d, s905w or s912 android tv box and then forget android completely and install LibreELEC or CoreELEC or equivalent instead
Kodi 17
Kodi 18
more info for you below