Retrieving and updating a BusinessPartner's standard email address via WebService

Hi guys,

there are web services like

BusinessPartnerERPByElementsQueryResponse_In, BusinessPartnerERPByIDQueryResponse_In and BusinessPartnerERPUpdateRequestConfirmation_In to query, read, and update BusinessPartner data:

http://es-workplace.sap.com/socoview(bD1lbiZjPTAwMSZkPW1pbg==)/render.asp?id=D50C65690DEA11DC5A11000F20FCB6A9

Apparently, they lack support for indicating which email address is the standard email address of a business partner's address. There is simply no field in the message structure to indicate the "standard period" (Note: Do not confuse this with "ValidityPeriond"), which is modifiable using a transaction like CIC0.

Why? I.e. is there a rationale other than "SAP just forgot to implement it"?

What would be the best way to remedy this if this information is essential for the service consumer? Enhancing all the interfaces and implementing BADIs?

Thanks in advance