Phil,
Thanks for your reply. I decided not to continue running TransDEM on my Mac through Wine/Crossover. Instead I've got it set up on my PC Laptop, and transfer the route files to my Mac via Dropbox. I do, however, have one issue. Not sure what can be done here, but it exported fine with one problem: the entire layout is invisible, no map, no terrain.
Now, I'm wondering if I should have added UTM tiles. I didn't do that the first time, so I'm going to make the assumption, that I should have in the first place.