[upstarter]

> I still wipe my phone and restore from iCloud after I've made my way through customs or border control.

It's not enough to just re-install the OS. You have to have your hardware recycled (discarded). Within a couple of seconds, they can put spyware onto your firmware by simply inserting a prepared USB device. The only way to get rid of that kind of spyware is to destroy the hardware.

The other solution is to not travel to any totalitarian countries or to travel there without any hardware, if you must.