[DK on the road]

All, I can only speak of #784. As we exposed the pipes, in the middle of my bedroom floor, the shower, toilet, sink and washing machine all were separate 1 1/2" lines and all dumped into 1 big tank. We had a hard time determining which was which at the tank. As it turned out the toilet that I needed access to, was behind all the others at the tank and we needed to remove a section of each for snake access to the toilet line.

#784 doesn't have a grey water bypass (that I know of).

It would be nice to have had additional flow from the shower or laundry to help keep the line that cares the most solids, rinsed, but in my case, this is not true.