[iaresee]

Not the OP of this thread, but for our setup the phone is just for the CGM. The pump (Tandem T-Slim) talks directly to the CGM (Dexcom G7) and doesn't need the phone as an interface between them.

The phone just sends the CGM data on to the cloud so we can see his numbers any time.

I also have a NightScout setup that's downloading his CGM data and saving it for us. It's not strictly necessary for anything we're doing, but I like the saved data and it's was useful for working with his Endo when they hadn't yet bought a Dexcom clinic license.