If I didn't think that Wonder Watt already had a long list of desired improvements I'd suggest that they could make the energy flow arrows thicker or thinner to represent the volume of energy flow. And not to bother showing an arrow if the flow was negligible e.g. less than say 20W. But even with Wonder Watt's steady rollout of updates and enhancements, I'm sure there are a load more urgent things to do, plus there seems to be a growing range of equipment suppliers to provide for.
In the end I expect the System Energy Flow diagram will gradually transform into a dashboard, with the next day's expected solar in kWh shown next to the solar panel icon, the number of Agile half-hour-slots set and the kWh expected from that next to the grid icon, the expected home consumption in kWh, and the current battery charge in kWh. And drill down options if you click on a particular icon e.g. you click on the grid icon and it takes you to the Agile Schedules page.