Investigation from APM has shown that the IFW on SOI manager machine is acting as a web services client.
As an aside, details such as the namespace are visible in the body of the response, this is why the server side (WebServices|Server) of the APM monitoring of the SOI manager process is actually reporting correct values.
Release : 4.2
Component : Service Operations Insight (SOI) Generic Connector
So it is normal for IFW to send an empty SOAP body.
There is nothing that can be done on APM side in the current implementation, there is no way for it to determine the details of the webservice.
The GenericConnectorService in SOI has multiple web service operations, so it would be misleading to hard code the haveEvents call for the WebServices client in webservices.pbd configuration.