or even better ... a kernel backdoor to expose hidden encrypted filesystems and false physical disk size reporting, with a specific userspace trigger (eg: open the password manager, when this password is selected destroy the hidden filesystem(s); when this other app is opened and the phrase "X y Z" is typed, expose the hidden filesystem as a disk to userspace).

You can go on forever with this stuff, especially if you have root on the device. Which gives you some clues about the true purpose of laws like this and who thinks they are useful.