I have an MU6470 (UK model) firmware v1270.3 and when I play a sample with the following characteristics:
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main 10@L5.1@High
HDR format : SMPTE ST 2094 App 4, Version 1, HDR10+ Profile A compatible
Codec ID : V_MPEGH/ISO/HEVC
it shows as HDR on the telly.
Hope this helps.