I received the official upgrade to Kodi 21 a few days ago. On my Nvidia Shield Pro this meant that my mkv files that included DV content now light up the Dolby Vision icon on my LG tv. (How good the picture was is an entirely different subject).
Kodi on my Aura was similarly upgraded and I used the same NAS located file but the LG did not recognise DV, just HDR.
I’m thinking that the Aura has a similar problem to my LG tv which will not recognise DV unless it comes from an HDMI source, not Ethernet/ external drive. I suspect that the Aura does not look for the DV marker in the file and therefore does not trigger the TV to handle it.
I don’t stream so I cannot test how Aura apps process DV from them.
Whether the Aura could properly process mkv files after a firmware upgrade does seem rather academic as we doesn’t seem likely that we will get one.