The binding strength of stage -> type is required.  Recommend changing it to extensible.  This aligns it with the binding strength in Cancer Stage Group profile - method (http://hl7.org/fhir/us/mcode/2023May/StructureDefinition-mcode-cancer-stage-group.html) which uses the same value set (http://hl7.org/fhir/us/mcode/2023May/ValueSet-mcode-cancer-staging-method-vs.html).

Also, the cancer staging method value set does not include all relevant staging methods.  Have a required binding strength would prevent the use of other relevant staging methods, such as the Toronto Childhood Cancer Stage Guidelines (http://www.iacr.com.fr/index.php?option=com_content&view=article&id=153&Itemid=657).