"BUT the development of advanced shocks has led to a massive reduction in size and so the space is readily found for coilovers for performance cars."

That is all I was trying to add something to, size. I work with shocks, I see a ton of stuff coming in and out of my work and their sizes vary greatly. Nothing suggests to me that "modern" one is more or less compact because its newer or older. Corvette damper is TINY compare to something off a 911. But are they that different in how modern they are? You size your shock size base on damping need and mechanical load cases. When you got a Caterham with nice motion ratio, short travel, and less load needed, you can build a small damper. That kind of condition may or may not be available in all cases, and damper is definitely not the first thing you design and pick when one is designing any car, let alone a packaging conscious passenger vehicle.

Yes sticking to tradition for the sake of it sucks, but sales and marketing drive that anyway(blame the customer? lol). Although I am not sure if that is necessarily the case in Corvette's design. One thing that is somewhat unique still in Corvette is that its still a body on frame car(another tradition maybe?), and most of the structural packaging is still in the frame rails. The leaf spring applies their load to the pivot and thats supported across the frame, and they can potentially(not to say they did, its my guess) have a much less reinforced damper mount that only takes damping load that cantilevers off the top of the rail in its own mount. The race car is built much different structurally since much of the frame was replaced/reinforced with cages and tube frame, they can get much better load path compare to the stock chassis without worrying about the same packaging requirement. Merit of sticking with body on frame instead of unibody? That I have no idea, though it does allow them to make all their models(hard top, convertible...etc) and not sacrificing structural rigidity with or without roof... Again, my best guess....