How-to prepare your files for machining equipment, spline, file transfers

We use engravers, laser cutters, routers and waterjets to use artwork from Illustrator.  I’ve been told by production that saving this as a .dxf (kind of works), but that their is no spline that a traditional CAD program might have.  I’m wondering if there are any better conversion methods that exist or that could exist that could better convert the curves/paths of items to manufacturing equipment as listed above.  Once upon a time there was Gerber and Omega but this sort of fell apart and was never upgraded.