FYI, thermal driver PR was merged yesterday. Kodi should show now CPU temperature. Also on the SoC which have GPU temperature sensor (A64, H6), gputemp command will show GPU temperature. On H3, gputemp show same temperature as cputemp.
Just checked temperature on my x2:
While watching zattoo it raised via 56 to 58°C
Uptime 1h 38