@BDub agreed on compatibility. However, I don't believe we use the STM32 "sleep" mode and thus why I only mentioned "stop" and "standby". Given that "sleep" is not implemented on the Core (it is really a re-packaged WiFi.off()), will it be implemented on the Photon?
I touched on VBAT here:
The power drop event (interrupt?) needs to be handled via a callback IMO and some use cases need to be illustrated. 