With the patient help of bortimus showing me the precise spots, I was able to locate the fabled ridge on my own end - at least the one on the 18th at Mulligan Municipal.
They do appear in the game, but not inside Unity, neither in the green mesh nor on the base terrain (last image). That means that these are real and that they have to go. Problem is that I have no idea how to deal with them.
I will start a corresponding thread/help request in the private CF forums. Knowing how assiduously the devs react to observations posted over there, I expect to get a competent answer from them
...soon
