If you just use the heightmap + Terrain Editor, you'll end up with a logo + spikey mountains. Then you use the altitude sliders along the bottom of the editor to 'clamp' the high and low altitudes. That flattens your logo, if you want. You can also use the scale control back in the main program, remembering that vertical is 'Z' in Vue.

Several of us where just using this method to create 'lightning' models, for a challenge in Corucopias Lighting & Atmosphere thread.

Also, as Bruno pointed out in another thread:
"..'Filter Altitudes' button in the terrain editor ( 2nd icon from the left in the upper right corner of the terrain editor), then use a filter from the round clip collection."

I'm also a fan of AltTerrain Builder.