Dolby Vision is supported in Kodi 21 Omega, but only if your device already supports DV, such as the nVidia Shield. Omega is in the alpha stage currently and a long way off from release, but it works surprisingly well. You can also install something like the Kodi Maven build of 20 Nexus, which has DV support backported. Both support DV in MKV. I'm running both on the Shield (Maven's build installs alongside Kodi's official build).
https://repo.kodinerds.net/index.php?action=list&scope=cat&item=Binary (arm64-v8a)
Get the one in the middle, remove ".zip" from the filename and sideload. You'll have to rescan your DV media into your Kodi library.