I thought about partitions for my Bantam T3C, but decided against it.
I have an Action Packer hinged box, ARB fridge, 15 ga. poly water tank and chuck box that stay in the trailer. When I calculated that even the thinnist of plywood, multiplied by only two partitions, it ended up consuming just enough space to prevent me from fitting in nested milk crates for consumables behind the chuck box. [photos at the link in my signature.]
I used a plywood floor for my trailer (covers the waves and imperfections in the original floor of my '46 trailer), then marked the location for the large items and bolted (not screwed) ordinary footman loops through the plywood floor. The box, fridge, water tank and chuck box are held in place with nylon straps.
Another negative for partitions vs. large items and containers strapped in place is that you will create many dark cavities and corners for stuff to collect, while adding needless weight and something else to rattle and squeek.
My two cents.