[noggin]

can anyone who own this device tell me if it can smoothly play in Kodi, streamed via WIFI or on Ethernet from local SMB share

-4k 10 bit HEVC HDR

Also is there some bug/issue if we play 4k HDR files on 1080p TV or 4k (no HDR) TV?

I think it depends on your definition of 'smooth'.  AIUI this device is still stuck at permanent 60Hz output - so any 24fps content will have 3:2 pull-down added, and any European 25/50Hz stuff will be even worse.

(I think unlike other Chromecast stuff it doesn't even allow the option of permanent 50Hz output?)