Having experimented the hell out of Fractal Terrains, I regret to tell you that this is just not practical in FT. The most realistic-looking results you'll get in FT are from the program's ridged multi-fractal algorithm, but they'll never produce results you could reconcile with the patterns that plate tectonics creates. At best, you'll get something more like Venus, which has an active core but no convection and therefore no continental drift to speak of (because it has no relatively high-paced planetary rotation that could be regulated by a tidally-locked body like a moon), so in the absence of true continental drift patterns, planetary venting happens in random locations (read: random volcanoes everywhere), which results in a blotchier, less patterned surface. It can be done prettily, if you like that kind of thing. But it'll never resemble realistic earth-style plate tectonics.