I have been using the NEXAT stuff on the map and havn't had any issues, they definetly need to work on the NEXAT stuff though, Spray won't disengage from the carrier unless it's unfolded, which is annoying. but that's not the map's fault.
I had the same problem, I ended up painting in a little more grass along the roadway and it seems to have fixed the problem, never crashed Courseplay for me though, just got stuck in "Field Detection" when starting an existing course.
