namirda, thanks for this very useful app.
If weren't for the limitation of Google Earth and KML, the mission tour would have been more accurate. Heading and altitude are interpolated linearly between waypoints in the actual flight, but since KML <gx:flyToMode> only allows value of either 'smooth' or 'bounce', there are no option to have linear interpolation. Unless a workaround is to split more segments between waypoints when writing out the Tour section to closer resemble a linearly interpolated heading and altitude.
I've a small request, if possible could you add some options for waypoint flight path lines width and area style fill/outline settings in VLM setup panel would be great. I find myself kept having to manually set the area style to 'outlined' only as I find the fill is too obstructing.