It looks like the graphs in the metrics-by-layout dashboard by default truncate the Y-axis to match the range of the displayed data (here's an example from our page creation dashboard). Having an option, either in the metric specification or the dashboard configuration to remove the truncation would be really useful. In our case, this is motivated by our interest in showing the change in data from an infliction point, where a truncated Y-axis results in changes looking larger (relatively speaking) than it otherwise would.