ArcGIS Pro 3.0 API Reference Guide
ArcGIS.Core.CIM Namespace / CIMCompositeCallout Class / CornerRadius Property

CornerRadius Property
Gets or sets the callout corner radius in points. 0.0 corresponds to a rectangle corner.
Syntax
public double CornerRadius {get; set;}
Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

ArcGIS Pro version: 2.6 or higher.
See Also