Win11 HDR Calibration app is a GAME CHANGER! LG C1/CX HDR settings for Auto HDR on PC

Settings for LG C1 OLED: HGIG, color gamut Auto saturation 55 Warm 50, brightness 48, fine tune dark areas 3 (or better brightness 50 fine tune dark areas -5). PC Mode Game Optimizer mode. Nvidia control panel RGB Full 10bits
Windows 11 HDR calibration first slider all the way to the left, 780 for the other 2 sliders, color saturation 0.

Note: I learned by watching a @Gaming Tech video that fine tune dark areas affect just the lower end of the gray scale so in that case it's better to use the default Brightness instead and adjust the black level with fine tune dark areas -5