Will indicate on the QuestionnaireResponse.item.answer.value in a comment: Note that all elements for complex answers provided in the QuestionnaireResponse SHOULD be the same as those allowed in the Questionnaire, however not all elements will be propagated and some systems might use language translations resulting in different displays.  Comparison of value to the values defined in the Questionnaire (whether by answerOption, answerValueSet or answerExpression) SHALL NOT pay attention to Coding.display, Reference.display, Quantity.unit unless those are the only elements present.  As well, systems are not required to check for a match on any extensions (e.g. ordinal values, translations, etc).  Systems MAY enforce that if extensions such as ordinal values are present in both Questionnaire and QuestionnaireResponse, they match.