@fleawig said:
Thanks, that's very helpful. Perhaps if I do the whole intersection operation at a larger scale, then scale down the results at the end--that could work? I'll try it out. (As well as your other suggestions.)
That's a good idea, but still the segments have to be greater [in number]. Importing a larger file MIGHT give you better curves, but the dome likely has to have more facets and scaling one up alone won't do that.
It may be a good idea to do the trimming at a larger scale because SketchUp has difficulty creating very small faces. It's OK however to scale down larger faces once created.