Our CEO is last tier for approvals for leave >1 day. He would like the ability to correspond privately with the Team Manager 1 level down the approval flow chain within the application, instead of emailing the Team Manager to discuss any concerns. This way the concerns are within the application, can be easily referenced, and remain between the CEO and Team Managers (not employees).
Team Managers tend to approve most if not all vacation requests. This puts the rejection always in the hands of the CEO. Allowing the private correspondence within the application, would spread out any rejection to include the Team Managers, not just the CEO.