What picture settings are you using? And do you use the dedicated PC mode?I have not actually used R709. I've gone through v389 which was atrocious, v645 which improved a lot of colour bleeding/blurring, and now v649 which I have to say, is another improvment and is at the moment, awesome. I never had the HLG issue, or could not identify it if I did.
Since update to v649, I've used the PC and streamed 4k HDR Netflix (Defenders and Lost in Space). The colours are more natural but very colourful without being over the top, no bleeding at all, and us noticeable sharper, clear and more defined. Specular highlight very sharp and detailed.
It could be all imagined, but it does seem clearer.
I wanted to return the tv after a week, quite happy with it now