Sounds like you want their Zero Data Retention plan: https://platform.openai.com/docs/guides/your-data#zero-data-...
(It's "contact us" pricing, so I have no idea how much that would set you back. I'm guessing it's not cheap.)
it doesn't seem like this would supercede a court order
The court order doesn't require OpenAI to modify their software. ZDR is implemented through a separate API with separate endpoints that never retained data in the first place.