Even though USB Restricted Mode has not been enabled in the iOS 11.4 final release, Apple has not yet dropped it, or even tried to improve it, to eliminate the possibility of hacking through the Lightning Jack. Now that beta iOS 11.4.1 is available and iOS 12 at a fairly early stage can be installed on devices, Restricted Mode returns with small changes that make it even safer than it was in the past
USB Restricted Mode was initially detected in previous beta versions, stopping access to data transfer via the Lightning Jack if the device was not unlocked with the user's password or fingerprint for more than a week. So, any hacking attempt using Celebrite or GrayKey hardware solutions was useless after that term. Given that there is plenty of time to crack the phone in a week, Apple has little changed functionality in the latest releases
Both in iOS 11.4.1 beta and iOS 12 beta, USB Restricted Mode enters into force after only one hour of inactivity. Thus, connecting new accessories or connecting to a PC requires a PIN or Touch ID / Face ID authentication to connect. The only thing that can be done without authentication is the power supply from the socket, the charging capability being still active
Even though this system is much safer, there is still the possibility to extend this period. If the phone is connected to a "known" PC in less than an hour, the connection will remain active indefinitely, while the timer starts only after the phone is disconnected. Thus, having access to a user's computer, the one-hour limitation can easily be extended.
As iOS 11 will not get too many updates and the feature is still being tested in iOS 12 beta, launching the new Apple phones in the fall and the new iOS 12 will surely be the time when we see USB Restricted Mode in its final version.