It's actually very easy to reduce the centering force for the warthog with very easy mods.
There are three ways:
1.) Extend the shaft. This will give you more accuracy and less centering force.
2.) Unscrew the top 8(?) screws from the silver ring and the four black screws hidden under the 8 screw silver ring. Remove the black heavy spring and place the four small springs from the bottom on top of piston through the rods.
See this tutorial:
3.) Replace the bottom four springs with more powerful springs. In my case, I purchased a pack of assorted small springs from homedepot and stacked 4 small springs on top of the bottom springs.