we haven't met but I'm on G dock and I think you are on E Dock. I did a complete refit of my CS30 holding tank and hoses last winter. The CS30 holding tank is configured with the pump out hose attaching to the tank about 5 inches above the lowest part of the tank. This configuration prevents completely emptying the tank at pump out time. Peter at Holland Marine sells a retrofit fitting that fixes this. A strong stomach, rubber gloves and it can be installed quite easily.
Page 294 of his online catalog.
I'll walk over this summer and introduce myself.