914 flying with both fuel pumps ON

A question in our Dynamic WT9 forum in Brazil raises the doubt about a bulletin issued by the company that assembles this aircraft in Brazil with the following recommendation for aircraft with Rotax 914:

"In order to maintain system redundancy and increase flight safety, it is recommended to fly ALWAYS with the main and auxiliary fuel pumps ON"

As I recall reading the manual and in subsequent Rotax bulletins, I do not remember this recommendation. 

Someone to give an opinion on the subject?

Thank You,

Marcelo