Implementing HCM in a live CX Sales/Service instance

Hello community, I hope you are doing well.
We are implementing Oracle Fusion HCM in a Fusion instance where Oracle CX Sales and Service are already live and operating in Production.

As part of this implementation, we need to update Worker information for existing employees - Address, Citizenship, Email, Phone, National Identifier, Payment Information, Contact, and Vacation/Absence Balances - and, as an example, we have already updated the Hire Date for a Worker.

Since CX Sales and Service are already operating in this same instance, we would like guidance from the community on what to consider during this HCM implementation so that it does not unintentionally affect the CX Sales and Service that are already running. Specifically: