I have a 2500 tank that I've only ever used for inversion. I use the 2509n insert for 6 sheets of 4x5 and fill the tank to cover the film when the tank is upright. The top of the tank has the red cap that the smaller Jobo tanks have, and I'm not familiar with the rotation hardware at all. I have never had a sheet dislodge, but I tend to agitate rather gently. I have not used the "paddles" that came with the 2509n.