tj, we have a 2012 283ts, and I've done a lot of mods to it also.
One thing I found is an extra space behind a false panel under the kitchen sink. It's to the right of the drawers. The panel pretty much just pushes in, and behind it is a nice large cubby hole. I lined it, bukilt a small raised floor, and its perfect for large tall items, like a collapseable broom, large cutting board, and my large griddle.
Also, if you remove the dienette cushions, and remove the thin plywood panal, you'll find two large hidey hole spaces behind the back of the pull out drawers. Perfect place to hide stuff while your out.