cut off a coil, the new diameter of the spring is about half inch too wide for the spring perch. The spring will sit in the perch, but half of the coil end will be off the edge of the perch; and it will not seat properly... even if you flatten the tip. It will sit in the seat. But IMO, it is not safe. Maybe you have a special technique for doing this correctly, and that is great. Good for you. But my concern is that some guys are going to read this post, and think it is sound engineering to go out into the garage and just start cutting coils off the ends of their springs to lower their cars.
Why not just get coil overs and do it correctly? There are lots of guys here with cars practically into the ground, so you can't tell me you want to go lower??