I think that the OP was referring to the 2 "paddles" that direct liquid into the reel's core area (probably what you're referring to as well).
Originally Posted by L Gebhardt
I also think that removing them is incorrect. These paddles also help to locate the reel within the tank. A quick check with mine reveals that removing them leaves the reel sloppy in the tank; allowing it to move around within the tank, and possibly causing the sheets to move. By design, the films' stability is highest when the force comes in a radial direction (around the circumference of the reel). If this not centred, the liquids can cause the edges and/or corners of the film to be lifted within their track/groove. With enough non-uniformed radial force (such as would be caused by an out of balance reel moving within the tank whilst agitation/spinning is occurring), I can imagine the film could be fully dislodged from this groove.
As for the paddles' use in inversion, there is no difference in their application/intention if used horizontally (rolling) or vertically (inversion), for as long as they're immersed, they will direct the liquids in to the centre in both cases. I would use them for both so as to maximise the refreshing of the developer on the inside sheets.