There were early (pre-publication) versions of Terracide in which I experimented with the approach in Reality's pdf, although I didn't get into as much detail. In the end, I found the Hero System had enough optional rules (including those in various supplements) to make the Flight power function the way I needed it to. For simplicity, I took the necessary optional rules (IIRC: Segmented movement, Cumulative flight, Modified turn modes, Fuel dependency) and bundled them into a single -0 limitation. I might have included Side Effects (rocket exhaust) as well.
One thing I never got around to was relativistic flight, since it was pretty much unheard of in Terracide. Nice work on that!