John:
One of the easiest ways i've found to reduce or eliminate most fin damage recovering on Plastic parasheets is the use of a spill hole.
Generally a 3/4" or 1" hole is all it takes depending on the size of the chute, to all but stop the "air spill wobble" inherent to all Plastic parasheets.
You'll still have to deal with decent rate and first touch down issues but having the model NOT swinging wildly around on the chute as it decends greatly reduces the impact even in pretty stiff breezes
Hope this helps a little.