This idea sounds wonderful on a Powerpoint presentation. But I can't see how it would be possible to quickly achieve a production rate of 500 units/month "on-demand". The proposal to produce the rail using rapid prototype processes like DLMS is probably not realistic. CNC machining from bar or extrusion would be far faster and cheaper. If they want to minimize lead time, they should focus on optimizing the CNC machining process, minimizing any dedicated fixture/tooling required, and designing the rail so that it can be produced on a wide variety of common CNC machines.
The most important thing they can do to reduce lead time for getting these rails into service would be to pre-qualify several established, reliable vendors to supply them on short notice.