That is almost never a problem. It has to do with winding order and the only time you need to pay attention to it is when creating polygons from some sort of other data like lidar. Even then any groups of connected polygons can be made to have consistent normals.

Why do you think that is difficult? I think your attachment to csg might be wishful thinking, you still have to get arbitrary shapes out of primitives, work with deformations, figure out textures etc.