How do I tell apart two hardware versions on one connection?

Dexcom data is returned exactly as Dexcom's API provides it, without splitting by hardware version, so readings from two device generations on one account…

Dexcom data is returned exactly as Dexcom's API provides it, without splitting by hardware version, so readings from two device generations on one account aren't distinguishable in device_data.

Better device-type differentiation is a logged enhancement. Until it ships, there's no reliable in-payload separator for simultaneously worn devices.