Apparently selecting a range of scenes in Scenes -> Update does not replace the current selection, it adds the range to the current selection.
Intuitively, I expected that selecting a range would de-select previously selected scenes. As a result I spent a significant amount of time making updates only to find that my scenes were not the way I intended them to be (because I had updated a change in a scene I had not intended to include). Possibly expressing my frustration audibly. This is a show with scores of scenes, so it wasn’t like I could just check all the scene update indicator arrows without scrolling through the whole list.
The Firmware Reference Guide doesn’t really say what is supposed to happen in this case, so this could well be the intended behavior. It felt like a bug to me until I realized what was happening.
So I guess my advice is to make sure you carefully check the update indicators before hitting “Apply” or else habitually start hitting “None” before selecting a Range if you don’t want to act on the previous set of scenes as well as the new range.