There's a difference between locking a phone and entering Before First Unlock state. After a reboot and before authentication the credentials stored on a phone

There's a difference between locking a phone and entering Before First Unlock state. After a reboot and before authentication the credentials stored on a phone are locked down much more securely, to the point (most) apps can't even start in the background. Locking and disabling biometrics are good ways to add a quick layer of protection, but rebooting makes it incredibly difficult for exploit kits and other hacking tools to dump the contents of a phone's storage. I'm thinking this may just be a bug (how often does a real world iPhone get zero available networks of any kind? Probably not enough for that use case to be tested thoroughly for days) but with how hard law enforcement is panicking about this, maybe it should be a feature. If they care this much, I don't think their expensive hacking subscription they've bought is working anymore, so it's probably working around some pretty bad vulnerabilities in iOS.