Personally, I wouldn't take it out. All my horse who we float in a two horse straight load, USE the divider a lot! We have a camera in our float and a hobby of ours is to evaluate how they float and what makes good floaters/bad floaters. We have found that the good floaters (most of ours) lean a certain way on the corner, and those probne to scrambling lean the other.
But a common factor we find, is that they lean on the divider/wall (depending on the corner) to compensate for the pull of the corner. Without the divider, they ahve to compensate for it themselves.
Because the divider doesn't go to the floor, they can still spread their legs to maintain balance as well :]