A good way to visually test whether you are actually getting a 10 bit end to end display is do this:
1. Create a special testing display profile with gamma set to 1.0 and enable it. This is important to do otherwise you can have a hard time distinguishing 8/10 bits. This will make your display look quite bright with little contrast wherever you are not color managing things. Ignore this during the test.
2. In Photoshop create and fill a long rectangular gradient from RGB 0,0,0 to 16,16,16 on a 16 bit mode new image. Set the Photoshop background to black or dark.
3. Assign it a gamma=1 profile. If you don't have one, create one in Photoshop by altering Adobe RGB to a custom gamma=1.
4. You will see 17 strong, vertical segments if your path is 8 bits anywhere. If 10 bits, you will see about 64, much narrower segments which may be barely noticeable.
In Photoshop settings select "desaturate colors" and make sure the % is set to 0. On Windows this causes internal paths to be 8 bits and you will see the display show the 17 vertical bars. Deselect to return to true 10 bit mode. I don't know whether Apple OSs differ with this selection.
I've attached an image to download with a gamma=1 profile attached you can use to skip steps 2 and 3.