Hey, I got and idea of how could train tracks be constructed in a similar manner as seen in the E3 trailer (elevated with support pillars). The system could be implemented on top of the current one.

The different construction and slope modes could be switched between using a keybind (CTRL? ALT?). On all types of elevated track, support pillars could spawn. These would have a limit of how deep down they can go (200 meters?), not appearing above the void.
Feel free to ask questions in the comments.
Thank you for reading, Ondar111