NESTT has been gone for a bit of time and you seem to have remade it, but if people want to straight up play NESTT instead, they'd like the train because you don't have to worry about the train going directly into an enemy base.
The trouble with the train is that it needs tracks. I tried making a train that just goes straight forever, but after about an hour it hits the edge of the map and crashes.
Perhaps merging some of the code from (https://mods.factorio.com/mod/DeleteEmptyChunks) would help.
Have the mod clone a set of tracks into the chunk ahead of the train and delete the tracks in the chunk behind.
Examine how the "Warptorio 2" mod spawns planets, and have your mod do the same at the beginning of the game, setting width to be infinite and height to be 124 or so (just enough so that a fully zoomed out view doesn't show the void.
However, when I read about this mod, I automatically think of "Snowpiercer.
Massive train, circling an entire planet. Tracks leading off ahead and behind as far as you can see ....
