Thanks - good catch! I'll go back and fix that.
I got a response from Rampa in Tech Support that the main problem is that the displacement map is not being exported correctly to Unreal Engine. If I go into the boot material (in UE) and dial back the amount of displacement from 1.0 to 0.05 the boots are more or less correct. I say more or less, because in CC3 and iClone they have all the detail that I sculpted in using Zbrush and baked into the maps, and most all of that is lost in UE to adjust for the bad export. Meh.

Here's a shot in iClone showing the correct surface texture