The amount of segments used to represent a curved feature is based on assumptions. For example, an editor may interpret a mapper’s input by merging points that are too close together. Many aspects of the editing process depend on the drawing of curves, and many parameters are assumed by an editor.
A drag is a gesture well suited to mapping curves. Instead of lifting from a trackpad - an event which can throw the mapper’s precision off - the mapper drags along the feature’s centerline. Such a mode provides more consistent levels of mapping detail, a speedup in which a mapper can trace features, and a more natural feel to mapping. However, it requires more assumptions by the editor used.
In order to draw a line, one may drag from a way. The same gesture may move the map using merely a capacitive touch. I wonder what the current state of dragging is in all of the editors. Does a feature lack curves because it is closer to an urban grid or because it is tedious and/or arbitrary to map.