As far as independant rear steer. Go to the Dial menu, set up one of the DT buttons to Ch4 with a 20 point step value. You can then control the rear steer independantly using the DT button you assigned.
I am trying to use rear steer on a scaler. I did your set up work great. I am having a problem with the rear steer not wanting to auto center. So when turning with the front only the rear will turn because it is not locked to center.
Can this be done.
"I want to have the rear axle be locked when not using the rear steer"