Cannot set to 10-bit display output?

Hi Folks
My 2nd monitor is a Benq 2711u capable of full 10-bit output. On the dual-boot windows I have set it to 10-bits but the Linux driver nvidia-settings for 450-57 only shows me 6/8 bit options. How do I enable this?

Nvidia-Settings-No-10-bit|538x500
Thanks for your help and suggestions!

I set Xorg.conf depth values to 30… the 6/8 bit in Nvidia-settings UI is only for the dithering it looks like…

As a further test I ran the NEC 10-bit openGL demo app using Wine and confirmed that the 8-bit sample shows Quantization when displayed on an 8-bit monitor with dithering disabled and the 10-bit shows a smoother rendering with a wider dynamic range on the 10-bit monitor with dithering disabled.