[Cider9986]

Or just don't wipe your phone and let the reboot timer do its work and bring your phone to BFU state, effectively uncrackable.

[cogman10]

The issue here is CBP was (illegally) demanding he give them his passcode (5th amendment violation).

Doesn't really matter if the reboot timer is triggered if the thugs have beaten your code out of you.

[blooalien]

There's an XKCD for that: https://xkcd.com/538/

[unethical_ban]

Or turn your phone off while transiting airports. Not a catch-all solution in life, but considering the extra-lack of rights we have there, it makes sense. No need for them if you write down your confirmation number before arriving for departure, in order to get your ticket printed. On landing, have it off until you clear TSA and Customs.

It shouldn't be this way, but oh well.

[pstuart]

At least disable biometric login.

[Andromxda]

And fully disable the USB port (GrapheneOS-exclusive feature). This will make it impossible to extract data with mobile forensics software/devices (such as the Cellebrite UFED).

[Cider9986]

Grapheneos has pin+biometric second factor as secondary unlock so it should be fine if you use that.