You can use a large wire with all wires installed in the 1st position and a round bar in the second and third position.
This will work in both corn and beans.
I had to take wires out of the second and third concave in beans with both my 1460 and 1660 or I had rotor loss. Using the large wire in the first position will give you good initial separation and the round bars will stop rotor loss. In corn large wire in the 1st position won't hurt you and the round bars in 2nd and third will really get the corn out. The first vane in the cage can also be put in a slow position for beans to hold the crop over the first concave longer and this also won't hurt you in corn.
I am using Case round bar concaves in my 2388. These concaves are made with round bars instead of the square steel in the large wire concaves. The bars are farther apart and have large wire through them in order to help hold the cobs and husk in place.
There are three concaves and the third position is the one in rear or toward the back end of the combine.
The round bar concave does not plug and does not grind the corn up. The corn sample is the best I ever had. Rotor loss is not measurable in corn and my only limit is the engine horsepower.
If I had the hp of a 2588 I could run 6 miles an hour in corn with an 8 row head and have low rotor loss. Now I run out of hp and the engine rpm drops in high yielding corn.