Wish I could help, but I don't have any 10 experience. I'd search properties/xconfs for lines containing a combination of following words (or something similar) wt.doc.WTDocument, attribute, creator. I'm guessing you can create a comparable entry for EPMDocument.
It's a shot in the dark, but I've got codebase\wt.adapter.delegates.properties with an entry:
DefaultAttributes.WCTYPE|wt.doc.WTDocument=name,number,checkoutInfo.state,department,description,docType,domainRef,folderingInfo.cabinet,format,iterationInfo.branchId,iterationInfo.creator,iterationInfo.identifier.iterationId,iterationInfo.latest,iterationInfo.modifier,iterationInfo.state,lock.date,locker.id,lock.note,masterReference,ownership.owner,teamId,lifeCycleAtGate,state.lifeCycleId,state.state,thePersistInfo.createStamp,thePersistInfo.modifyStamp,title,versionInfo.identifier.versionId,versionInfo.identifier.versionLevel
Maybe you can try a similar entry for EPMDocument