Could passive mode be implemented on another device?

[vitawasalreadytaken]

Hi, thank you so much for this project! I am new to BLE and have a probably very basic question.

I got the example app running on an iPhone alongside the Dexcom G5 app. Now I'm wondering if it's possible to implement this passive mode – meaning eavesdropping on the communication between the transmitter and the Dexcom app – on a different device than the iPhone running the Dexcom app?

The way I understand BLE this should be possible – the other device would not communicate with the transmitter at all, just listen for the messages intended for the iPhone and decrypt them using the transmitter ID...

(My project is to build a wearable device with something like https://docs.particle.io/datasheets/mesh/xenon-datasheet/)