Im afraid you need a different set of springs . There should be no compression of the springs at all until the weight of the car is on them .
This is why Leda and others make different strut lengths for different disciplines i.e' Rally - a longer body and damper ,
Race/Tarmac /Road rally - a shorter damper and strut tube
you should be careful that shortening the springs on their platform doesn't mean you run out of suspension travel !