The Identity Hub can't officially store audit dates against attributes. It stores the dates against operations, and then the attributes are linked to the operations. So if you have an HL7 message arriving with different dates on different attributes, you end up having to execute a number of MemPut operations. So it CAN be done, but it's messy, and I'd be a little concerned about performance, in that instance. Of course, if you go to Update mode as well (instead of Snapshot mode) then an inbound message is likely to contain only one set of dates (business and technical) anyway so would only occasion one MemPut.
Incidentally, I don't think eDrug has a requirement for Update Mode. Current Pharmanet demographic updates to CRS are considered Snapshots, so if they don't change an address, they still have to supply it. The Update Mode requirement is probably coming from somewhere else, though.
