Thanks for the detailed issue report. I am experiencing the exact same issue with the same scenario (I invited myself as a tester and redeemed on a device using a personal Apple ID, now I can't re-invite myself to the same app using my work Apple ID even if I delete myself from "all testers".) Waiting 90 days to resolve this seems unreasonable especially as it's unclear this would actually resolve the issue. I can't figure out any other action I can take inside TestFlight that would allow me to generate a new invite not locked to the old tester Apple ID. As the old feedback here has appeared to have been ignored for over a year, I have opened a new feedback at FB22398790 to attempt to re-escalate this issue.