color grading REC709 using clean feed output

Hi all,
what do you think ?

I got a 2000hours EIZO CG247x for a little price.

Is it ok to color grad in REC709 using the clean feed output only using Nvidia card HDMi output ?
It looks OK but not sure ...

Other related questions:
- If I use a HDMI2.0a cable out of a nvidia 980ti, 10bit 1080p, could I switch clean feed from 8 to 10bit for color grading in P3 for example ?
- Can the old 1080p Decklink monitor pci-e card send the "Enable HDR metadata over HDMI" signal to tell screen to go in 10bit mode ?

Thanks !

I've found an interesting option in nvidia control panel:
Color Accuracy Mode
Reference: Rendered pixels are processed through the GPU pipeline in 1:1 pixel color-matching mode. This pipeline is used if there are no pixel color enhancements from the OS or from color adjustment applications such as the NVIDIA Control Panel

nice step forward