Can we utilize an internal API for fetching non primary address details for a customer

We have a requirement to allow users to override the bill to or ship address to a non primary address in CPQ before creating an order / subscription. Currently, CPQ only stores the primary bill to / ship to details. We need to get the address details along with site use identifier to achieve this which involves making multiple API calls.

We came across the below REST API which allows us to fetch all the customer addresses linked to a party. However the API is marked as internal. What are the restrictions around this API that we need to consider if we plan to use this.