Apple Watch 6 blood oxygen measurement said I had hypoxia when I in reality was fine. How to know if reading is taken in optimal conditions?
TL;DR: How can I know if the SpO2 reading is in fact taken in optimal conditions ?
As much as I understand your frustration, Apple mentions the limits in the small print at the bottom of https://www.apple.com/watch/:
Blood Oxygen app measurements are not intended for medical use, including self-diagnosis or consultation with a doctor, and are only designed for general fitness and wellness purposes.