[Thebes]

Is that because when its fully loaded there isn't enough room for the liquid to move around?

It seems there isn't enough spacing between the slots, but even with slots only half loaded it lacked decent agitation patterns. I seem to remember a professor calling the effect bromide drag, but I'm not sure that was technically true. I got streaks on everything, especially evident in skies and on walls.
That I evolved a technique that kind-of worked with the yankee seems to be uncommon. Even with only haf the slots loaded I had to slosh it around so much that considerable diluted developer leaked out. It worked, but was a poor solution and I would not use one again. I sort of pushed and pulled it inside of a tray until it just barely lost any fluid with it a certain amount full.