Rav - One thought I had, and I don't know if it's an issue or not, is what map you exported from FTPro. If you exported the whole world in a single file and then zoomed in to a region you would get lots of terraces because each pixel in the global map is the equivalent of several miles in size. I have FTPro export a lot of map slices (a 30x30 overlapping grid of them). The area covered in this whole map I'm using is a single one of those grid slices. So each one of my pixels is 1/30th the size of a global pixel (technically 1/900th if you measure by area rather than just width). That could explain the difference in resolution we're seeing.

However, exporting that many map slices is time consuming. FTPro can do a single map slice in about a minute on my machine. To do this it builds 926 separate images (it makes some higher-level regional images too). 926 minutes is ~ 15 hours. And that's per layer I export - climate, water, elevation, rainfall, temperature, terrain shading, etc. I can see why most people don't take the time to mess with it in this way. In order to support this 3D I'm having to re-export the heightmap file to fix the water issue. It will finish in about another 12 hours.