Your company stores a large volume of infrequently used data in Cloud Storage.

To exclude a subset of users or projects from Data Access audit logging, you use the exempted principals configuration. This allows you to selectively disable logs for specific groups, such as developers in the CustomerService folder.

"You can configure exempted principals so that audit logs are not generated for certain users, service accounts, or groups."

— Configuring Audit Logs

"Data Access logs are disabled by default because of their high volume, and you can enable them at the organization, folder, or project level."

— Audit Logs Overview

Thus, enabling audit logging org-wide and exempting a specific set of users (i.e., CustomerService folder) meets the need.