Great breakdown of the migration paths. The cookie and session portability issue is the part that tends to get buried in the data format checklist, but it's where teams actually lose days. Ten credential flows to redo means ten rounds of password resets, MFA challenges, and service desk tickets. And the guidance to export session files as sensitive data without a secure transport mechanism is a security gap most migration runbooks don't flag.

For agent-driven workflows that depend on signed-in sessions, there's a structural fix worth considering. Decouple the identity layer from the browser. If agents authenticate to a programmable credential vault instead of borrowing browser cookies, the next tooling migration is a credentials config change rather than a ten-step re-authentication marathon. That's the direction some agent infrastructure projects like CAI are heading.