I suspect this is a feature of the rendering library. Using the same feature on the height layers will create contour lines. Implementing contour lines will then be quite easy. And it might even be possible to make them on and off switchable like the grid is.
Of course, the lines won't be labled with the height, so you still need the color gradient to determine the direction of the slope, but I think that is a minor issue for people wanting contour lines.
So, am I right? Could this feature be used for contour lines?
(PS: it is always nice when people say things are easy to implement without having seen the code.)
