Would a 12V disconnect fully power down the Pebble?

Maybe a 12V battery disconnect switch? Scout AI does not have a definitive answer on what happens to the computer/control system when the main breaker (B1) is turned off.

The Pebble can be woken from sleep via the app, which suggests the computer may operate on the 12V system rather than AC. It is unclear whether the main breaker controls power to the onboard computer specifically.