isInside / BRepClass3d_SolidClassifier alternative?

FreeCAD is using BRepClass3d_SolidClassifier to check if a shape is inside an object.
It is used for example in the CAM part of FreeCAD to see if an extension should be on one or on the other side of an edge.
It is very inefficient with larger models, since this check is performed for every single line segment of a shape.