You’re right @rlkoshak, this approach mainly requires the system to be able to identify whether the lock was engaged by an action physically performed on the external hardware (e.g., a button or code on the keypad), and users would need to get used to physically locking the door. I believe this could even remove the need for a separate alarm kit.
In this case, if someone is accepting a package and unlocks the deadbolt using the UI, it could be assumed that nobody is leaving the house.
Maybe even the case when the status of the presence item is OFF (home alone), disengaging the lock from the UI could mean there will be someone home.
Although the example of remotely opening the door for a delivery guy may complicate this scenario.