Those using this should be aware, the software isn’t being developed much anymore that I can see , - at least based on forum actiivity and lack of consistent feedack/posts from author, which would bother me a great deal plus given the fact this is expensive for PRO version where only ‘tiled’ output is possible.
There are free ways to make your own terrain and load into ue4 , using world composition to align them as needed, plus ‘L3DT’ has a ‘free’ version which while also as WM has no tiled output unless pro version is used, at least allows a far bigger map size than free version of WM.
Also lastly, the ‘scale’ issue talked about above doesn’t require that much ‘math’ at all, you just have to use the values as outlined at url below , based against 256m='100 units ’ scale in UE4 so there is nothing very mysterious or hard about it at all ):