> if you are the kind of person these exploits are likely to target, you should have it on

You can also selectively turn it on in high-risk settings. I do so when I travel abroad or go through a border. (Haven't started doing it yet with TSA domestically. Let's see how the ICE fiasco evolves.)

For entering the US you want to fully wipe your phone first. Lockdown mode is useless since they will just hold you in a basement until you unlock the phone for them to clone.