I was studying the ackerman on the steering and fixed everything at once. I run inline steering with all 4 spacers forward. I run the forward hole on the steering rack. Instead of adding a shim on the inner ball stud end, I lowered the outer. It has a single 1mm shim at that end. That's it. No bump steer and perfect ackerman steering geometry. I run 20 degrees of caster so this setup may not work perfectly for other caster amounts.