To my knowledge, the hydraulic functions can be managed through the A-pillar display. At least any functions the guys I’ve worked with need can be. Someone else may know more and can add to or correct me.

If the SteadySteer is old enough (Pre Nov 2021 Part Number 4004773-3 ), you would only need and All Steering Modes unlock and the installation kit for that tractor. If it is newer, due to a design change to deal with the supply chain fiasco of the time, you would need to obtain an SCM Part Number 4004773-1.