A developer built a FIDO2 hardware security key on an ESP32-S3 using Pico FIDO2 firmware, but OpenAI's Daybreak system classifies it as a Passkey rather than a hardware key, rejecting it despite successful registration and authentication. OpenAI Support confirmed that FIDO Metadata Service listing and attestation are not documented requirements, but provided no clear mechanism for the physical key to be recognized as hardware.