I updated my fm 750 to 4.0 and noticed in the ezsteer settings that there is an "advanced bubble" so I checked it out.  I don't know if I just missed it before or if it is new to 4.0.  It gives me the choice to either enable or adjust the following settings:  "Estimated Steering angle Bias",  "Dynamic Approach Angle",  "Steering Slew Limit",  and "Steering Acceleration Limit".  I checked the ezsteer settings in the 750 operators manual v.4.0 and it said nothing.   My dealer is very good and has not heard of any of this before.    Anyone know what they do?