If we add these values, will they cause crashes on our website and will they stop?

If we add these values, will they cause crashes on our website and will they stop?

We do not have to update the CNAME records for your entire domain (example: abc.com). We simply need to add new CNAME records for a specific subdomain, (example: s2s.abc.com) This process is akin to creating a new address within your existing property.
Adding these records for the subdomain will not affect your main website or cause any crashes. It's a safe and common practice for directing traffic to specific functionalities within a domain.