What’s the the cheapest way to add yield mapping to a 9870STS? It already has sensors. I can get a starfire ITC for fairly cheap. I already have a brown box and mobile processor in another tractor but no keycard. I can’t seem to find any keycards but i do see keycards being sold along with brown box which is still cheaper than other options. I can’t seem to find any 2600 displays and the 2630s are pretty expensive. Are there other non Deere displays that would work? Are the sensors on the 9870STS working with isobus? I see that Outback MAX/rebel and Trimble 750 support isobus. Just looking for any suggestions at all thanks. The 9870 is auto trac ready which is a bonus if that worked but not necessary.