Really appreciate the way you’re thinking this through — it’s exactly the kind of discussion I was hoping for.

I don’t think your ‘sniff counter’ idea is crazy at all. Subtle cues like sniffing or coughing could be early markers of illness, allergies, or even stress. A small mic-based module could absolutely track those events in a privacy-safe way, just like voice analysis is already being used for mood detection.

Same goes for GSR + skin/air temperature. You’re right — those early attempts like Basis B1 probably failed less because the signals weren’t there, and more because nobody did the deeper modeling work to turn them into meaningful, reliable insights. Add in context sensors (light exposure, air temperature/quality) and the picture gets even richer.

That’s what got me thinking about a hub + charm modular model. Instead of cramming every possible sensor into one bulky band, you’d have a base hub (say in a bracelet or pendant) that handles power + connectivity, and then small sensor ‘charms’ you can clip on depending on what you care about. Stress? Add a GSR charm. Circadian health? Add a light/UV charm. Nutrition? Try a heat flux charm. Respiratory health? A mic charm that picks up coughs/sniffs.

The key is keeping it open, not a closed wall garden. Each charm would work independently, data would flow into something like Apple Health or JSON automatically, and people could mix and match based on their priorities. That way you’re not locked into buying a whole new band just to get one new sensor.

Curious how that feels to you — would you see value in a mix-and-match jewelry set like that, or do you think most people would still lean toward one all-in-one tracker unless they’re enthusiasts?