No, there is no possibility to scan in the background without knowledge of the user.
We have to keep up with Android official guidelines, and launching "silent scan" without the notification is not permitted by the system - if you do so, your service might be killed in any moment, without your knowledge. We don't want this behaviour, so we decided to only allow scanning in the background using
foreground service with notification
If you need to be notified when user enters your zone, you might consider using NearbyAPI by Google, but we are not officially supporting it in our ProximitySDK for now.