onlyAllowTrueCurveUpdatesByTrueCurveClients property
True if the service only allows curve geometries to be updated by client code that identifies itself as a true curve-enabled client, indicating that client editing workflows account for curve segments correctly, false otherwise.
This property can only be true if ArcGISFeatureServiceInfo.allowTrueCurvesUpdates is true.
By default, this API is a true curve client when editing feature services that support curves, and curve geometries are fetched from services that support curves. Use ArcGISEnvironment.serviceCurveGeometryMode to change this default behavior.