I have being working with another aplication at work which has also the ability to design internal workflows pretty much like JIRA. It also has its steps and transitions, etc... However the one thing this applications does which would be a real enhancement on JIRA is that when you're looking at the workflow steps and transitions, on the side it also shows you graphically how does your steps and transitions are represented and linked between the multiple steps. This is a huge impact for the person building the workflow on helping to understand and visualize much faster if the end results is ok.