There is a new update available for L3DT Professional that includes two new features:
You can change the design-map parameters - such as erosion, lakes, roughness, etc - after you've generated or imported the design map. The menu option for this is 'Operations→Design map→Modify parameters…'.
An image can be 'draped' over the main map display as a semi-transparent overlay. This is intended to help users create design-maps by using images of contour maps (etc.) as templates or guides. The menu option for this is 'View→Image overlay…'.
Both of these features are still undocumented, and should be considered to have 'beta' status. They will be included in the Standard Edition in a month or two.
Registered users can download the update from the regular place…wink wink, nudge nudge.