According to technical data from the Sony site, the following 4K resolutions are rendered.

4096 × 2160p at 23.98/24 Hz
3840 × 2160p at 29.97/30 Hz
3840 × 2160p at 25 Hz
3840 × 2160p at 23.98/24 Hz

Since 4K 60 Hz is not supported, it must still be HDMI 1.4 - the reference guide does not specify a standard.
And with HDMI 1.4, no HDR support is possible.
Reference guide from Sony:
https://www.sony.de/electronic...

Greetings Thomas

I have tried to stream Netflix 4k from the PS4Pro, unfortunately without success, probably because it is only HDMI 1.4 which the box supports at most and therefore the Netflix APP blocks 4k! I assume it will be the same everywhere.
Luckily I have a powerful TV where I can run Netflix, and then just audio via the box, then 4k works. But very bad of Sony or simply unrealistic, up to the point I'm pretty satisfied with the box (except for individual annoying dropouts when looping through where sometimes picture and / or sound suddenly disappear for a few seconds during playback from PS4Pro, but most maximum 1 time per movie, therefore tolerable. Couldn't find out yet what the problem is).