I build a bunch of track sections in TrackMK and then welded them together in Zmodeler, created a new NCP for the new object and imported it into a track as an instance... Well, aside from the part where the NCP doesn't work at all, it also takes a century to load the 750k NCP file.

I have an elaborate track planned out that would require ~75 TrackMK sections. Assuming I import all of these instances and, in chunks, create a world file out of them using RVGlue - in the end, the NCP file is still going to take a century to load. This is starting to sound like a lost cause.