Wait what was the Switch 2 HDR situation? I'm not sure I changed any settings on my B4 or C2; I just see the HDR logo pop up in the top right corner when I boot up an HDR game. Although I think I use game mode because the input lag is ass otherwise, so the colors are way more vibrant. I normally just use FMM - never messed with settings manually.
lots of people apparently had trouble calibrating HDR on their TVs because a) their TVs don't support HGIG, or b) they didn't know how to raise and lower the brightness threshold without it over or under compensating. a future OS update added a peak brightness nit count, iirc, but this guy's videos were showing folks how to properly calibrate their displays based on the brand