There are multiple ways to use the duress PIN/password feature including writing it down on a phone case or a paper kept in a wallet. People should carefully consider how to use it in an actual duress situation where there can be physical or legal consequences for wiping the device. GrapheneOS doesn't require it to protect data from being extracted from the device, but it takes recovering it completely off the table even with the PIN/password for each profile on the device.

This is a important distinction. If you don't volunteer information, but someone guesses that the pin written on the phone unlocks the phone.. you haven't lied, or done any wilfill action to trigger a delete.