I use Ag Leader's Steady Steer to steer my Deere 9770 combine. I do use an InCommand for Yield monitoring so I do not have your problem. As Shop Teacher suggests, using a Guidance setup rather than a harvest configuration should work for you.

I was very impressed with using Steady Steer for combining soybeans. I plant with a 24-30 planter but harvest with a 35' draper head. The width of the head is exactly 14 - 30 inch rows. Of course, much of the time I am harvesting part of one planter pass and part of another planter pass. In other words the "guess row" comes into play. This works out OK since I do have a bit of "grace" with the 35' head.

Our corn and soybeans are planted with an InCommand and an Ag Leader GPS 7500 unlocked and subscribed to Terra Star Pro C. With our mostly flat land, the Steady Steer works fine for harvesting soybeans.

However, I was not satisfied with its steering in corn. Even though I harvest 8 rows, the inevitable planter/GPS drift makes the head alignment less than perfect in corn.

Since Ag Leader did not provide a feeler system for a corn head in the past (they do now), I went with a Truesight II feeler system for corn. It uses the Ag Leader Steady Steer motor but cotrols the steering based on the feelers.

This means that for soybean harvest, the Steady Steer motor is steering the combine based on AB lines. For corn harvest, the same Stedy Steer motor is steering the combine based on the feeler system. I need to move two connections when switching from soybeans to corn.

This may sound confusing but works very well. Had I to do over again at this point in time, I would likely go with Ag Leader's Steady Steer and a GO display to handle both the AB and feeler guidance situations.