Looks great for a prototype. Has any modeling, simulation, or analysis been done of its off-road performance, i.e. mobility, GO/NOGO, motive efficiency, maneuverability on deformable terrain? This is critical for agricultural applications.

Has any stress analysis been done on the frame? Looks to me like it could use a couple more triangles to reinforce those rectangles.

Have you designed a skid-steering controller for it? Off-road skid steering can be quite variable obviously depending on terrain properties.