*edit - Went out and purchased one anyway. I can confirm the "jellyfish-10-mbps-hd-hevc-10bit.mkv" file plays flawlessly in MXPlayer in HW+ mode. If anyone knows a way to show FPS or CPU usage, I can do some tests with other files and report back.
*edit2 - Using the debug mode in Kodi, I get the following results with the above file.
FPS: 60 (no drops)
CPU0: 55%, CPU1: 55%, CPU2: 25%, CPU3: 25%
No noticeable heat from the tablet after looping the video for 5 minutes, although I'll find out better when watching a film.
Available to test other files if anyone is interested in this tablet