Yes, but that only works for Garmin. The export format for the GarminShapingPoint is quite clear, as Garmin defines these already.
For a more general gpx export, we should think about an option. As I said, one option could be the type. Another option could be sym. For sym there seem to be different flags, it could be:
- Flag, Green = Start
- Flag, Blue = Waypoint
- Flag, Yellow = Shaping
- Flag, Red = Destination
This might help for some GPX viewers to better show the different waypoint types.
In any case, I am still looking for a good way to solve this for most navigators. I am not crazy about creating 100 different exports for every different GPX device 
.