That spray bar is a SPRAY BAR and I dont think the original way you hoped the drip plate would work can touch what you have going on there now. It looks like it drops alot of water very evenly- very nice. I wouldnt worry about the mechanical too much- if you run a sponge in your overflow your covered and/or the top layer of your biomedia which probably will be the coarsest will act mechanically for you. Thats too bad you couldnt fit it through the cabinet doors but the bright side of that is you have one big bad mama jama of a sump!