The latest release of Activiti Enterprise does implement a variation of Data Elements, however they are not compatible with the BPMN 2.0 Data store definition.
Rather, these implementation provides for mapping of database tables to an "Entity" definition. There is a blog that describes the Data Entity/Data Model setup you can find here:
https://community.alfresco.com/community/bpm/blog/2016/11/17/activiti-enterprise-developer-series-cu...
Hope this helps,
Greg
