8-bit RGB with dithering has less banding than 10-bit (which suffers from YCbCr420 subsampling as well) on the LG OLEDs. You don't need a 10-bit signal or a true 10-bit panel for HDR because the...

Serial SATA is UASP.
Additionally it will show up under Device Manager > Storage Controllers as well if it's UASP.

That's probably preventing the gamma table from being written in GPU memory somehow. It will probably cause other problems and a performance hit when writing to GPU memory.

There is a workaround using DisplayCAL Profile Loader. You need to get the Windows profile converted to work with DisplayCAL though.
http://hub.displaycal.net/forums/topic/how-to-adjust-gamma-alone/

The Windows display profile usually only works in borderless window mode. Games that use full screen exclusive mode usually reset the gamma ramp. Windows would restore the gamma ramp when you quit...