It is clear how to set person-level profile params via the API. However, I am setting up an integration in which I want to be able to upsert (Klaviyo) client-level parameters that would accessible to all lists and segments in the same manner as person-level profile params, but without having to update each person any time a client-level param changes.

For illustrative example: Assume my product integrates with ACME Co (A) and sets a product_preference parameter in the profile of each customer. Assume I want a “default preference” to apply in any case that a person’s profile does not have a product_preference set. Client A may want to change that default preference from time to time. And, when they do, I want a way to represent that choice at the account level instead of having to repopulate the change across every known “person”. Is there a solution to this problem? Can that solution be implemented via an API endpoint?