they keep doubling down on HRV metrics

except optical HRV at the wrist is garbage

it cannot even measure when there is any movement

you'd think someone would come up with the technology to use the skin contact as a single lead ECG without requiring a second contact point by the other arm (or leg)

guess that's a generation or two away

suunto has the right idea with their tiny movesense ECG and it's even open-source