Comment by nwalters512

A use case this doesn't address is embedding across two completely different domains, which is pretty common in the education space with LMS platforms like Canvas (https://www.instructure.com/canvas) embedding other tools for things like quizzes, textbooks, or grading. I ended up in a Chrome trial that disabled third-party cookies which broke a lot of these embeds because they can no longer set identity cookies that they rely on from within their iframe.