@Star97: For your peace of mind, it is only possible to access the Secure Folder on your device using the security features you have in place, or your own Samsung Account details. If the phone is returned to its factory settings, all personal data would be removed, so no need to worry.
If you have lost your phone, why not try signing in to Find My Mobile via the link below, as you may be able to locate the device, or remotely manage it to keep it safe. I hope this helps.
