[noggin]

HDR on Intel/AMD (and nVidia GPUs) is still very WIP - and limited to Windows currently.   A large number of us are using other solutions for HDR - as there are <£150 solutions that play 2160p50 and 2160p60 10-bit HEVC content with HDR10 output with far fewer hassles than a Windows equivalent (and for a lot less money).  These solutions aren't perfect either - but they are cheaper. As a result I think they get more Kodi fire-power aimed at them for HDR.

Some NUCs (and other x86 barebones systems) had Displayport 1.2->HDMI 2.0 conversion internally to handle 2160p60 and 2160p50 output, as HDMI 1.4 was limited to 2160p30 and below.  This caused issues with HD Audio and/or HDR (and 3D for those still interested in that) in some cases on some platforms. 

You'll find a lot of love for AMLogic S905X/D and S912 platforms running Libre/CoreElec (or OSMC) here and nVidia Shield TV too.