In airplane mode and even while turned off, phones have been known to still transmit data via background services. Leaving it behind, or a Faraday bag are the only assured options I’m aware of

What’s the scale of the graph? 1:1, thousands?

Does this work with multiple device accounts? Work requires my phone to have a personal/work account to be able to access applications like teams, and it’s the only thing keeping me from swapping