It can get even worse, guys. A friend is an engineer for a company that makes springs. (small ones!) With many designs, as coils are removed, the effective spring compression rate changes. This implies that any shortening of any type spring will alter is compression geometry as compared to the full coil version, or one of the same height OA, with a different compression rate.
I am NOT an engineer, but have studied this with both automotive valve springs, and springs built for our military in various weapon systems.
For example, consider shimming a valve spring, as compared to using either a stiffer and shorter spring, as compared to shortening a spring.
As I do considerable work with Alfa oil pumps, it's interesting to me to note the number of pumps from trashed engines that come in with shimmed relief valve springs. These springs are in constant motion (hopefully!) when the engine is running. They are designed to take a set, and shorten with use as they become tired. They require replacement rather than shimming, as the shimming alters the designed in compression rate. A shimmed spring, has a different compression rate than the same length spring without compression. A shortened spring of the same compression rate, is a different animal entirely. Try it with a valve spring at different heights of compression and you will see what I'm talking about here.
In Alfas, as far as I know, the suspension springs are designed to be shimmed for height and compression rate, not cut. Now, that said, this is JUST MY OPINION based on my experience. I am sure that a spring engineer can cut a spring and get a useful and proper result, if he has the facilities to test his result and knows exactly what he is trying to achieve.