Workset is editable, but you can't edit the element until '[Borrowers]' resaves the element to central and relinquishes it and you Reload Latest.
Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 26.2.0.0 (26.2.0.0)
Syntax
C#
public static FailureDefinitionId CannotEditElements { get; }