I remember working on the clutch in my ‘77 AW400 and it was miserable. My buddy used to work on his by jacking up his truck, sliding the bike under, and lowering the truck using the frame to compress the clutch pack. 😁 There is a difference I think with the Maico disc springs vs the diaphragm. With the stacked discs the spring rate is unaffected by the radial stress on the center of the hole in the disc. On the diaphragm spring compressing the spring should reduce the size of the center hole. Since there is a ring preventing that compression the compression in line with the fingers provides another torsion. I think that’s how the reduction in rate occurs as the diaphragm passes through flat.
I never said the diaphragm clutch was new. Just that I never saw it explained in a way that made sense to me. I’m still learning.