Marcus,
I think your on target with the distrobution of force idea. However they do account for the bleed it creates in the rebound stack, take that "distributor shim" out and you have major problems with rebound being slow.. BTW I first saw this in 96 with the RM midvalve where you had a stationary pivot shim, which really adds up...
Another Intresting thing I've learned about the backing plates on midvalves is they are not there to control area or limit area growth but to rather prevent the shims from over opening due to fluid momnetum and destroying themsleves.. I've conducted lots of exsperiments on this with my Solid Clamp Midvalve concept, and it does not do what "we've" allways thought it did...
Later!
Jer