Elements are still visible while a device is locked

I’m trying to write a test where I’m interacting with a hybrid iOS app, then lock the device for some duration, then unlock the device and resume interacting with the app.

I noticed that regardless of whether I’m successful unlocking the device (this is itself problematic… Cannot unlock screen in iOS device (Simulator)), I can remain in the same webview and continue to interact with the app. Appium acts like the elements are still visible when the device is locked. Short of using some visual testing software, it seems impossible to write a meaningful test case while this is true.