Dropping a note in here so I can get updates to posts.
The original Bug Out was a basic 4x8 square drop. This was to facilitate simplicity in the build in the hopes to encourage people to build their own trailer. It is simple and cheap requiring little cutting since all panels are as you would purchase them at the hardware store except the end pieces. If you can paint and wallpaper then canvasing (PMF) is usually within the abilities of the average person. A simple Harbor Freight trailer is economical and more than enough trailer (in fact overkill) to support a Bug Out body. A square drop is, as someone mentioned, more roomy for the same foot print as a traditional tear drop shape. I did not include shelving or doors to simplify the build. So yes the original Bug Out was a box. The builds we are doing for for the site does come with two shelves with a front lip in the rear. Extra Door, baggage doors and windows can be added for additional costs.
The Bug Out is a foamie. The benefits of a foamie is that there is little to rot. With traditional builds you have to make sure everything is sealed properly or you can potentially get rot. Even if traditional built trailers are sealed properly when new, you still have to make sure the seals are in good shape from time to time. Sadly, usually by time you find you have a water intrusion issue it is too late, and expensive repairs are needed. This is more the case if the trailer is used on rough roads often. The way foamies are constructed there is little way for seals to fail, since there really is no seals on a foamie. If a seal did fail, if there was one, there is nothing to rot if water did get inside the skin.
A foamie is also super light compared to a similarly sized traditional build. A 3/4"x4'x8' piece of plywood weighs about 61 pounds and supplies very little insulation value (R-.94). A 2"x4'x8' piece of XPS foam weighs about 8 pounds and has R-10 insulation value. You can see this makes for a well insulated and light build.
Foamies can recover from slight damage. Yes they can regenerate and heal if the damage is not too extensive.
Ok, well hope this answers a few questions. Thanks for looking, George.