I woul say that designing is one thing, grinding a lens so the correct specifications is another story. OLSO is great for design but won't help you to get the real lens. And don't forget that for each lens, you have 2 faces to grind in a concentric way.
Astronomers don't grind lens but mirrors: 1 face to polish instead of 2. Surface accuracy has to be much higher but the Foucault method of control is rather easy to implement (even if some parameters has to be well choosen and measurements have taken seriously).