what I assume could be described as the... man I don't know.. I guess the boundary layer, the part that makes contact...
I seem to be getting the best results using -1.0 (negative 1) for the ground.
Would this create a negative collision vector, or anything wonky? I mean so far objects seem to bounce in the correct direction but I feel intuitively this would change the normal and give me grief later maybe?
It seems to be working great for me.
0.0001 puts added objects a bit too high, 0.1 ironically lets objects sag a bit into the ground but -1.0 seems dead on.