[DantePL]

There is a pending pr (https://github.com/xbmc/xbmc/pull/19983) that adds the ability for Kodi to detect the type of HDR in a file (HDR/DolbyVision/HLG) and display the correct flag in Estuary.  It can't be merged currently though as it changes the JSONRPC and thus no further backport fixes for it for v19 will be possible.  Once v19.2 is released, it should be able to be merged into v20.

Thank you very much for your reply. This is fantastic news!
I will be waiting (im)patiently until then

Sooo, I stumbled upon v20 Nexus Alpha 3 Kodi build quite by accident and started diging into changelogs since Alpha 1 and was mezmerized by this entry from Alpha 1: "New media flags for HDR videos: detect, store and process the type of HDR in a video file". I installed Alpha 3 without further ado and YYYEEESSS! - the HDR flags now whow up in Estuary. Fantastic! Thank you! Customizable subtitles are also cool! Great job