CDM v5.3.1 was recently released. It mainly consists of documentation bug fixes and updates to the BigQuery and Impala DDLs to make them more compatible. The largest change is a renaming of 8 columns in the VISIT_DETAIL table to make them more compliant with the OHDSI naming convention. For example VISIT_DETAIL.VISIT_CONCEPT_ID became VISIT_DETAIL.VISIT_DETAIL_CONCEPT_ID. The full list of all changes is available on the github. Please let me know if you have any questions!