With the release of GroupDocs.Conversion for .NET v19.11 you can now monitor Document Conversion progress and status using C#. There are way many Conversions supported by the Api, that are listed in the Documentation.
A new property Listener is added. The Document converter listener implementation is used for monitoring Conversion status and progress. Have a look at ConverterListener class that implements IConverterListenerinterface
Below is the usage
Coming to the improvement, MPP to XLS Conversion is improved....Conversion for .NET v 19.11 you can...can now monitor document conversion progress and status using C#...