[DW SD]

I'm guessing that the increased mechanical motion can turn into heat energy. (conservation of energy) Any coil spring (or torsion spring for that matter) gets hot when it is cycled fast enough.

I suspect I'm not adding much for you, but that is my guess. The material properties of all of the springs would be similar, as are the tolerances, so they'd all see similar stresses and have similar breaking points. A specialist like camgrinder would probably tell you if all of the other springs will begin to break (or not).

Hope that is the smallest bit helpful.

Doug