Dear Caetano Almeida,
I checked the Badi MD_CHANGE_MRP_DATA through se18 where used list. It is used in only standard program. And how to check the CHANGE_MDPSX_MDUP, CHANGE_MDPSX_MDUA, and CHANGE_MDPSX_MDUB.
Here you can see that Ord.Ds is of 2 required quantity but it not reduce the available quantity. This for same for all other components.