The business manager and the product owner are requesting a more flexible way to incorporate...

The project manager should identify adequate change management tools to conduct the project, as this will help them to manage the changes to the product baseline in a flexible and efficient way. Change management tools are methods, techniques, or software that help to plan, execute, monitor, and control changes in a project. Some examples of change management tools are change request forms, change logs, configuration management systems, traceability matrices, and change impact analysis. By using these tools, the project manager can ensure that the changes are properly documented, evaluated, approved, implemented, and communicated. This will also help to minimize the risks and costs associated with the changes, and to maintain the quality and scope of the product. References:

Change Request Form: Definition, Types, Process & Tools

Change Log Template - Project Management Docs

Configuration Management: What is it and why is it important?

Traceability Matrix in Software Testing with Example Template

Change Impact Analysis - an overview | ScienceDirect Topics