One modification you might consider is to ditch those European cabinet hinges [which were never really intended for this kind use IMO], and install a piano hinge on the bottom edge of the door. You would also need some kind of surface latch(es) at the top, to keep the door closed.
With this mod, the entire space would be more usable, and nothing will be in the way when you slide containers/stuff in and out. You could probably figure out a combination of Sterilite containers which would fit snugly in the entire space, in order not to slide around during towing.
Yes . . . not exactly why you got a brand new Airstream -- to modify the cabinetry!
-- but sooner or later you will get around to lots of mods like this IMO.
In any event, have fun with the 25', the same model we used to have many moons ago!
Happy trails,
Peter
PS -- Ditto to Dan, Bob and Terry as to the purpose of the dividers.