The APP window will hide traffic on the ground, but you'll have to tell it where "ground" is. This is done either in the ASR file as explained in chapter 2 of the Developer Guide, or alternatively in the plugin's settings file (using the Airport_Elevation and Airport_Radius settings).
As there are many ways the runway extensions are depicted in various setups around the world, I believe it's best if the plugin just offers a simple default option, and any other types are created as plugin maps. There you can define the layout (colors, line types and widths, text labels, etc.) exactly as needed.
