As said above when you cut a spring you increase the stiffness.
In terms of mechanics there is 2 other concerns:
. On the cutted end of the spring you don't have a closed end which is not good in terms of contact.
. The number of active coils must be an odd number of 0.5 in order to balance the upper and lower reaction forces and avoid the bending of the spring. In cutting a rebound coil to get just a kissing contact you may need several iterations and you are not sure to get this condition unless you cut an entire number of coil... but with what gap at the end?
After several miles the gap may increase due to the materials fatigue. The SSL design allows to adjust the gap easily in the time by adjusting the pre-compression of the upper spring.
