HDR is terrible on this. I had one and I felt ripped off. It is a scam - it can read an HDR signal but it ramps up the backlight so blacks become grey, colours become washed out and frankly way worse than SDR which looks reasonable on this set.
Don't go near it if HDR is what you want - you will be disappointed.
There are surprisingly few sets our there which can do HDR justice.
The cheapest is the Samsumg KS8000 - I ended up gong LG E6 OLED after taking the Sony back - and Currys knew exactly what my issue was and returned it with no quibble.
If people here think that HDR looks good on the Sony, they need to see HDR on a set that can properly display it.