Why? There is no reason they should be designed to be fully compressed at maximum engine torque, in fact it would be foolish to do so. I would design them to withstand full engine torque PLUS whatever transient and shock loading might be anticipated in the system.
Many clutch plates in ordinary powertrains have radial shock absorbing springs.
However under full torque transfer, (maximum acceleration), these radial shock absorbers placed in the torque path will already be fully compressed.
Why? And what does "fully wound up" mean? - that the drivetrain is at its elastic limit? - again it would be foolish to design the drivetrain to be at its failure limit under these conditions.
Any other parts of the powertrain capable of wind up will also be fully wound up. (bit like me I suppose )
I didn't say anything about these items "assisting" the shift mechanism. You asked how the next gear could increase the speed of the output shaft when the output shaft is connected to the rear wheels and I answered you - the connection is elastic!
Therefore non of the items you list can play a part in assisting the shift mechanism when it is asked to transfer torque during your suggested maximum torque upshift.
I should modify my original statement to say "engagement of the new gear increases the speed of the output shaft slightly while simultaneously reducing the speed of the input shaft. This allows the dogs (bullets) to disengage the previous gear."