The source McProfileEdges does not have to have the same parent McLineProfiles as this one. It is just used to set this instance's properties. Edges and WeightedProfiles are not copied.
An object manager property change notification is fired with ID_IMcProfileEdges_CopyFrom after all of the properties are set. And then if the IsStale property went True during the CopyFrom operation an object manager property change notification is fired with ID_IMcProfileEdges_IsStale.