I try not to have a seam roll onto itself on the backing. The more you roll onto the rail the 'floppier' each side of the seam gets. I try to either 1) piece triangles with a diagonal seam or 2) have seam run across the pole.
I also don't worry where the seam is, down the middle, 1/4 way in, one, two or three seams. It's just the position of where the seams land on the pole for me.
Try it both ways and you will see what I mean. I know it takes time, but it is better to see for yourself.