I don't need to cut down my rebound springs, (happy with SSL) but on a technical point surely this would leave a nasty end on the wire which would not sit flat on the adjacent mating faces top & bottom
When you look at the existing springs the last turn is brought in a little tighter so that when its cut off and ground flat you're left with a continuous circular face on each end to spread the load
Not easy to describe, but if you look at one you'll see what I mean