Enhancing Mapping in Esourcing Datatypes

Hi, I am having problems with enhancing the ESO messages and having the data pass if I use the data type enhancement.

I found documentation that suggests you directly enhance the standard data type. Is this correct?

http://go.sap.com/documents/2016/06/b245a65a-767c-0010-82c7-eda71af511fa.html