Don't be sorry. It's sad that N3V won't release that information to third-party developers such as Dr. Ziegler who could update his flagship program to handle the latest data formats. They could do it I suppose under license like many developers do but sadly they do not. Tony, to his credit did mention that they may consider doing direct DEM support but who knows when. It would be nice if they partnered with Dr. Ziegler and integrated TransDEM capabilities within the program.
N3V never offered direct support for anything like the tiles and that's done through scenery objects like the basemaps. This has its advantages and disadvantages, but it works.
The ground structure is different in HD terrain from what I understand. N3V for one got rid of the edge of the baseboards and the terrain is tessellated to add in the additional faces and increase the resolution. If they did it right, this could be applied to areas where needed instead of globally on a baseboard or route basis. Imagine tessellating just an area near a ravine or mountain slope to increase resolution there and nowhere else unless it's needed. That I think would be much more efficient overall.
, I admire your courage but will not copy your example with the current beta. The introduction of HD terrain is far too big a change for me to risk using the beta for my projects. I will wait until the "final" version is released.