Agree with the intent of the issue author; however, this change would be a significant compatibility break without a concomitant increase in functionality or interoperability. Further, it's difficult to justify such a change during ballot resolution, given that systems are in production. We will revisit following publication to engage implementers on such a change. We are tracking significant, proposed changes to evaluate following resolution, to enable implementer feedback and experimentation: https://github.com/HL7/fhircast-docs/wiki/Proposed-breaking-changes-following-STU3-publication