From what I've read about how it works, I would have thought FFB would be better in LFS than others. Myself, I've not been surprised by anything the FFB does in any situation in LFS and I can't say the same for any other sim despite very minimal usage. Too quick to judge soundly, no doubt, and there's nothing specific I can put my finger on, but first impressions and all that
One thing I do miss from a previous, crappy wheel I had was rumble. This was some thrustmaster/ferrari thing with no FFB (bungee cords for an always-on centering force, yay), but had a rumble motor. Made a world of difference when feeling for an apex when you're looking past the exit.
Perhaps there is the possibility of an option to exaggerate the force of FFB when it is changing rapidly, like a force multiplier based on a very short history of change rate. I would guess that would effectively make a rumble-like effect on curbs, but who knows if it would really work like that, or what else it might screw up. Just thinking aloud
Blackrabbi: Have you tried fiddling with the castor angle of your set? You can dial FFB force in and out with setups, but especially castor angle. Higher force might help you feel the bumps.