I stow mine under the drivers dinette seat. I had to modify a brace is all to allow room, and put some cleats on the bottom that keep it in place nicely. However, since they started using a larger black tank, which takes up more space in the dinette seat, they also started putting a lot of the electrical stuff in there too, which I believe would eliminate this spot.
However, I can see no reason why it could not be stored under the dinette bench on the passenger side, but maybe someone with a newer 19 could confirm.