How do you have three sets of settings? Is this on the same HDMI input? How do you switch between the three without having to input your changes? ThanksYes, stay with ISF Dark but set Gamma to 2.2, especially if you are not in a pitch black room.
If still shadows too dark, set brightness between 53-55, see what works. You may rise the absolute blacks but I find it more easy on the eyes. I also drop the contrast to 70 - 75 for dark room but that is personal preference not accurate white level / black level. Right now I have a setting for viewing when my eyes are tired with OLED Light - 23 / Contrast 70 / Brightness 57 / Gamma 2.2. But that is not accurate - just easy on the eyes.
I have three sets of settings that I use depending on room lighting or mood - one with OLED light 80 and the other default settings from "ISF Bright", another with the same settings but OLED Light at 60 and the dim one mentioned above for when my eyes are tired