After my personal crusade, the developers provided control of the size of the color swatches.

Excel to this day still does not provide control of color swatches in any of its legends, or perhaps I have just not found it.

The benefit of less work and less time to create a chart or plot can come at the cost of needed or wanted capability.

I recognize that band plots are very, very popular. In most cases, perhaps people don't care about providing the precise numbers. They may just want to provide a rough visual comparison over time. Easy is always a natural solution, even if sub-optimal in consequences.

Data tips were mercifully available for HTML in ODS Graphics from the beginning. However, in the case of the band plot, the automatic data tips would be for the y values, not for the difference at each point between the current y value and the y value of the line below if. For SAS/GRAPH, I could provide such customized data tips. For ODS Graphics, I have no immediate idea how to do that.