Yes, the current mapping assumes source and target are semantically equivalent (one-to-one “Maps to” relationships), need to be split into several parallel concepts (one-to-many “Maps to”) or need to be split into EAV (“Maps to” plus “Maps to value”). We don’t have aggregation maps (like in your case), maps to number/unit combinations or more complicated situations where mapping results in concepts of different Domains. We are working on a proposal that will allow all these.