I'm going to start documenting IFrame credentialless: see https://chromestatus.com/feature/5729461725036544

This feature was first available in Chrome 110.

Also see my research doc here, for more details: https://docs.google.com/document/d/17mT4HI-dRnt6wT58907ubrkyhu1HjTiIH4JAIBqjKng/edit#