They must be doing something that integrates user-contributed data because one quirk of their course planner[1] is an out-and-back plan along the same course will have non-coincident elevation profiles, even along trails where it can't be explained by switching sides of the road.
1: And their planner, in general, is garbage. I usually take the output file and run it through an AI system to fix it so it doesn't try to cue me to pointlessly switch to the other side of a major road and ride on the sidewalk.
1: And their planner, in general, is garbage. I usually take the output file and run it through an AI system to fix it so it doesn't try to cue me to pointlessly switch to the other side of a major road and ride on the sidewalk.