The rafter tails are exposed only on the outside, not inside and use a different material, size and spacing than the internal ones. Haven't tried to mess with this yet and for the external/landscaping model, I could probably just change the framing specs if the rafters would show. The documentation says you can have different gable options for each side, but my initial testing of a simple gable didn't allow that. No matter which roof edge I selected, changing the gable appearance changed the selection for all gable appearances for the roof. Not that it really mattered, since in 3D, it looked like the exterior wall material was used for the gable and the roof gable material selection was ignored. But like I said, just initial testing & could be operator error.
The roof tool populates the valleys with tile. I need "no tile" in those areas. The valley surface level is noticeably lower than the top of the tiles. Suppose I could do the roof with Surfaces, but probably not worth the trouble. Yes, probably could try to use a dormer for the cricket. Have the fireplace, but haven't used it in many, many years. No big need here in Central Texas. Still shows on the outside though.
What I really meant about the large terrain size was that I plan to use a lot of trees, plants and exterior detail = many objects. Using a quad processor with 8 GB mem, so not really a wimpy box, but even Sample 1 doesn't load instantly...
From reading posts, I had already understood about the additive nature of the plateaus, but thanks for pointing it out again.