I’m not sure if hiding an encrypted partition of feature would be beneficial.
The fact that someone could hide his data will be known from everyone sooner or later.
So there could very well be an escalation of distrust from security staff about people saying that they hide nothing.
In the end, won’t they even try something like lie detector ?
Just like the article says, you should leave any useful data at home or separately from your phone.
Would it be possible to have it on an encrypted microSD card which could be removed at any moment ?