It's unfortunately a solid centre, it's a pretty brutal bloody thing to try and engage smoothly, fingers crossed with some more average driving it may settle down. I was told that sprung centre at this power level will only be good for dampening out idle clutch noises. As at the torque levels the car is making, the springs will have to be that stiff, they pretty much become redundant?
I have spoken to them, no guarantee the shudder will ease up with one cushion disc. Here's to hoping it eases up for me, more so for the gearbox and my cv's sake