Forgotten - There are some flags (for Lux) you can set for the mesh. 

mesh::N         normal[n]       Per vertex normals over the mesh        none - optional
mesh::P         point[n]        An unordered list of vertex positions in the mesh.      none - must be specified
mesh::acceltype         string  Accelerator structure to use (auto, bruteforce, grid, kdtree, none, qbvh)       "auto"
...

C4D-Exporter is using "acceltype". Don't know what it exactly does, but it seams to work :)

---