Option for trailing 4 weeks/12 months in graphs

I love the simplicity of Weightbot, and the interface. However one simplification I find limits the usefulness. The monthly and yearly views are a great use of screen real estate (lots of data history), but the fact that it is bound to a month/year is problematic as each new month/year begins. Why have a chart with one data point, lots of wasted blank space, when there is good data available? Why not have an option for the month view to be the trailing 30 days (or trailing 4 weeks) and the year view be the trailing 12 months.