Add Activiti Attributes to default type

Hi All
I have been stepping through the code seeing how the default type like bpmn:UserTask is created on the modeler with the id and the businessObject…etc. My question is that, if i just want to add some additional activiti attributes in the businessObject like something in camunda in this type. Is there a way to extend this type and add those attributes in the businessObject without creating a new custom element, Since everything is the same like i wouldn’t have to have a customElementFactory or customUpdate or customRender. Please let me know if i am on the right path