Your migration plan includes transferring agent performance data.

To accommodate agent performance data within Salesforce, creating custom objects specifically designed to track such metrics is the most suitable approach. Custom objects allow for the flexible design of data structures that can specifically cater to the unique requirements of tracking agent performance, such as productivity, customer feedback scores, and other relevant KPIs. This flexibility ensures that all pertinent data can be captured and analyzed effectively within Salesforce.

References: https://help.salesforce.com/articleView?id=sf.customobjects_overview.htm