OpenSCAD's biggest problem appears to be that it is single-threaded. I learned this from a guy printing parts for my RV. Is there an open CSG package out there somewhere that does operations like Minkowski Sums as convolutions so that they can be expressed as multiplies in frequency space and then brought down to real space for tessellation? Not only could you take that multi-threaded but you could potentially run it on a GPU hundreds of thousands of times faster.