When EnableAsyncLoading is true, we will enable the LoadInBackground property which is available in PivotEngine. In asynchronous mode, engine values are populated only after background worker DoWork event is triggered.
“DoWork event is raised when you call the RunWorkerAsync method. This is where you start the operation that performs the potentially time-consuming work.”
In Asynchronous mode, the engine "Populate" method has been invoked finally. Hence, asynchronous mode performance is better than normal mode of pivot control. After populating the data, those values are rendered in the Pivot control.
It is already available in Pivot Grid and we need to implement the same support in the PivotChart control.
For further reference, please refer the UG documentation of Pivot Grid control from the following link: