So, again, I don't know anything about the device in question, so this is all conjecture... but:
Even given that OTA flashing is possible, why bother? The device has no means of waking the user without a phone in bluetooth range, so what's the upshot? I don't know that battery life falls into that category because the device would need some pretty serious upgrades, and cost would obviously increase:
- More RAM. Lots more. Enough to contain an entire firmware image during OTA and an entire night of sleep/movement history.
- More MIPS. Actigraphy isn't going to be as cheap as store-and-forward.
- A reliable RTC so that the device can ping the phone at the right wakeup time.
- etc.
If I was in their position, I'd build the device to be as dumb a peripheral as possible. Push the complexity out of expensive hardware and into software. I'd also probably have built in a sweet inductive charging pad, too, but I'm a sucker for shiny things.
