Thanks for your suggestion about the numbering system. I think visually its interesting. I've consulted with the team here while in Vancouver and at this stage the added complexity of using these numbering would be an added task for the team. Also, using numbering can be an issue if later we add further activities - this causes further work to change all the numbering into the correct order.
Rather than number steps we will give them 'labels' or small headings, so that you can refer to them later. Caroline is here during this discussion, so that she can clarify.