CHIPS is a nice solution, the problem is how it interacts with SSO IDP login pages. 99% of IDPs in an enterprise setting are configured to refuse being framed

CHIPS is a nice solution, the problem is how it interacts with SSO IDP login pages. 99% of IDPs in an enterprise setting are configured to refuse being framed (for "security" reasons). What does this mean? That any embedded component that needs to log the user in needs to trigger a popup window - but wait, a popup window isn't in the same cookie partition as the iframe! Some clever people at Google did come up with a solution for this, "pop-ins": https://github.com/explainers-by-googlers/partitioned-popins https://github.com/explainers-by-googlers/partitioned-popins , which would have allowed cookie partitioning without breaking every enterprise integration out there