I think that a bluetooth enabled lock is onerous to maintain the autolock/unlock feature. Just for battery concerns, it doesn't pan out to be something I'd care to turn on. The wifi ap seems to be an altogether better implementation for the lock/unlock feature, which should fall back to bluetooth when the power is out in the house. I can't really speak to whether your phone dies outside the house, but a good practice is to have a way to charge your phone from the car so that you can always get in the house if you can get into your car (and start the car).
In any case, I'm still awaiting the wifi ap to connect my android, as I still can't get the app to work on nougat. I also think that android doze may be causing issues that the sesame team hadn't anticipated, such that the optimizations on android are shutting down the bluetooth capabilities of the phone prematurely.
Please let us know the status of performance on the latest google phones running Android 7+. Not all of us have an iphone, and i feel that the cross platform capability advertised was premature. I understand that this may not have been the intention, but the fact remains that I can't even use the lock but my wife can.