My terrain is large - what is the world machine export process?

15000 The size of the world / 2017 reselution * 100 alwayse there, so
15000 / 2017 743.6787307882995 . I would shorting it a bit so 743.6787
I recomend you export it in 4033 and not tiled
Then you wuold get 371.93156 you will get a bitt better res