Our legal team believes we need to treat email preferences per email address, not per person record. This works great for Marketo's system unsubscribe field because of Marketo's Durable Unsubscribe logic. However, I can't think of a way to natively mimic this logic within Marketo for other fields. Unfortunately we have a lot of duplicates, especially at the customer level, which are purposeful.
So for example: Person A and Person B have the same email address. Person A unsubscribes from the Newsletter category in our Preference Center. How do I also update the Newsletter field for Person B to keep their preferences in sync?
Is there a way we should try to code this outside of Marketo using APIs?