BPMN and DMN models support version tag attributes in the XML definitions.
CMMN case models do not support the same attribute, and when you refer to a CMMN model in a BPMN model as a case instance you can only select "latest", "deployment", "version" and not "version tag" as you can with processes and decision tables.
Not being able to specify a "version tag" means that it's harder to resolve issues in a case instance without having to update and deploy other models first.
"latest" is not an option if the fix is to an older version (i.e. "version tag") instance of the case, as redeploying the older case means that newer business versions get superceded.