There are too many mandatories in DiagnosticReport. Requiring a full timestamp for a diagnostic report isn't reasonable - not everyone captures down to the millisecond. Resources shouldn't be enforcing good practices, only the minimum necessary to make the resource even vaguely useable/computable. If a system has a lab report PDF and can link it to the patient, it should be able to create a DiagnosticReport instance, even all it can populate is subject, code and presentedForm. (Maybe status). But to say that absolutely nothing computable can happen in the absense of effective[x] or issued or performer is absolutely false. It's good practice for those things to be present - so force them to be present in a "good practice" profile - don't force them in the resource.