SRM + MDG on single ECC

We’ve got a conundrum with the MDG implementation. There is conflict on the MDG and ECC6 combined vs MDG-ECC and separate Transactional ECC. They are having issues figuring out how to keep the two systems in sync and are considering moving it back into a single combined instance of ECC. The problem with that is that they need SRM_Server activated on the ECC box, but then you are not allowed to activate the MDG-S domain.

We’ve read the SAP Note 1491040 - MDG-S: Activating business function MDG_ERP_SUPPLIER and it says it’s a safeguard. But I can’t find anything in the forums about it and it’s from 2010. Any idea if you can get full SRM_Server functionality via MDG-S?