To make this clear to everyone:
Duress PIN/Password will work anywhere where the device credentials are requested. NOT JUST THE LOCKSCREEN.
Anywhere in the OS where the PIN/password is requested (enabling developer options, a PIN prompt to unlock an app, confirming your PIN to change the device's password, anywhere) can trigger the duress PIN.
The only exception is the SIM PIN prompt, since that's a different PIN, but we will likely extend it to that screen too, to try and avoid any confusion.