I believe that if the the stock springs had a set rate when they were wound, they will still be about equal to each other when they are shortened. I believe that aftermarket new springs will be about equal to each other when they were wound if a person buys name brand springs. I can check the spring rates. If they were within tolerance/about the same before modifying, they should be the same after modifying. Most aftermarket and some dealers cannot tell you what the rates are or tell
you what the tolerance is. Everything has a manufacturing tolerance.
After careful measuring of a suspension, I modify springs in pairs so they will be about equal to each other. If you yourself are doing one side of a car and then the other, maybe the springs you do, do not have the same spring rate. If slamming on your brakes causes your car to lean and swerve, I would look into working on the brakes to see why one side grabs better than the other.
& NUMBER FOUR: The biggest problem w/ cut springs, is that you have no Idea what sort of spring rates you have after you do it. Also, there is NO WAY to cut both sides so they come out w/ the same spring rate. This will give your car dangerous handling problems.
Imagine you slam on the brakes to save your life & the car leans to the Left side, causing your car swerve into oncoming traffic or to the right where there is a drop off from pavement to grass/dirt shoulder and you bottom out tearing up your oil pan or something worse.