I agree that sxi_monitor/ run time work bench or not exactly business user friendly.
There is another solution "Application interface framework" available for business user monitoring(Of course a separate licence is required 
)
Comparison on Application Interface Framework (AIF) and Process Orchestration (PO)
Also If you really need the response from the BAPI then i don't see any issue in having synchronous interface. It's not overused at all.
If your requirement is ensure message flow without any failures in PI, then you can configure alerts but this does not guarantee if everything went well during the RFC execution.