Tom, correct about the rear linkage. You are getting the rocker into its fastest ratio change range. Its not a hard tail, but its real stiff after about 1/2".
On the forks I used the same method we used in the flat-tracking days. Schedule 40 sleeves outside the tube for absolute stops, and Schedule 40 spring spacers to increase preload inside the tubes. The outside sleeve doesnt make contact, done right, except when tied-down for transport.
That was the fix for us poor guys that couldnt afford short Betors or Cerianis. In the beginning, we used to use steel or aluminum tubng, but aluminum against steel was bad and steel was hard to find in the right sizes. PVC or ABS never made rust inside the tubes.
I'm suspecting sliding a flat-tracker and running straight on salt have one thing in common: you dont want the bike changing attitude when the power is held on, or chopped momentarily. The wobbly bikes all had too soft front ends, it seemed. And maybe too much travel?
By the way, fellows, this isnt my bike so it wont be orange!