What functions would you want to add in a health fitness watch?

I have been wearing a Garmin Forerunner 265s for about 6 weeks and am amazed at what it can figure out once it adapted to my body physiology. It has sensors for heart pate and blood oxygen saturation, accelerometers and a GPS.
Of course it knows heart rate, HR. Easy. But how does it know respiration? HR is not constant. It increases speed slightly when you inhale and decreases when you exhale. From that lead and lag it determines breathing rate. It deduces other things:
– Stress level
– Heart rate variability
– VO2 Max
– Sleep quality
– Training readiness
It takes about 3 weeks to learn your normals and then works with those numbers to calculate other values.

What additional functions or values would you like to see in a fitness watch – even if it requires an additional sensing element?
I would add:
– Alcohol or THC impairment level determined from heart rate and motion
– Hot flash detection and tracking
– Blood pressure

What would you add?