How to prevent mails to people in CC for case update for a specific Business unit

Hi,

I am looking for a way to selectively control email notification behavior based on a Case's Business Unit.

The Requirement: For any Case created or updated within a specific Business Unit, I need to ensure that individuals in the CC field do not receive automatic email notifications (Case Acknowledgements). Only the Primary Contact should receive the email.

What I’ve tried: I found the system setting: "Send automatic notifications only to contact." While this works perfectly to suppress CC emails, it is a global setting that affects the entire organization. I need to keep CC notifications active for all other Business Units.

The Challenge: Since this is a global system toggle, I cannot find a way to apply it conditionally.

My Questions:

1. Is there a way to scope this system setting to a specific Business Unit without affecting the whole environment?
2. If not, what is the best practice for overriding the default notification engine for one specific BU?
3. If I have to disable the global setting and use custom flows instead, how do I ensure it doesn't trigger duplicate emails for the other Business Units?