Thanks for sharing all this stuff, Hunter. It's super interesting to see. Also, by making it available for anyone to experiment with, you've enabled the track building community as a whole to learn from it. I think this kind of free flow of information is key to the progression of content for this game.
I downloaded the files for the Clubmx main track and quickly threw something together to see how it worked. The trees really do mean extra work is necessary to smooth things out, or rebuild sections that go under them, but it's really impressive how rideable a lot of it is out of the box. Here are my files if anyone wants to mess with them: http://openlightpictures.com/pub/ClubMXMainTrack.zip
bastex.png - 8k overlay
terrain.exr - raw 32-bit export from Blender. Needs to be converted to 16-bit and linearized.
terrain.png - game-ready terrain. Still needs a lot of work, but it's rideable. I really roughly removed most of the trees, and I'm not sure if it's truly linear.
I don't intend to actually finish this track, I was just curious. So feel free to put these to use yourself if they are helpful at all.