Yes latest libreelec rom available here, also the latest android rom is installed to eMMC.
The steps are as simple as open a HDR/BT2020 file in Kodi and play it, on my other devices (Nvidia Shield and Himedia Q10 Pro) the tv detects a HDR signal and switches to HDR mode.
With the Khadas vim, it does not.
I tried Kodi in the latest Android rom and also in libreelec.
I will get the hardware date code soon, once I plug the device back in.