Can you track continuous heart rate during sleep and overlay it onto the "sleep levels" graph. This gives us an idea of how low/high the heart rate is going during sleep for an individual.
Conditions like Bradycardia. Microsoft health dashboard does this in an awesome way. I really miss this feature on garmin connect. I guess you are already capturing the heart rate and deciding sleep states based on that. Why cant you just show the bpm as a graphical line overlay-ed onto the "sleep levels" graph?
I am attaching a pic of sample microsoft health dashboard.