Don't ever go off road!
The rear can be a vertical cut... just sayin'.
The upper front can be "sharper", gaining interior standing room with I think no perceptible loss of aero.
Similarly, the boat-tailing of the roof and sides appears shallower than necessary, which unnecessarily cuts into headroom and floorplan room. I think the boat-tailing can start a bit later. Put it up against the aero template.
Something I'd like to see on trailers, which seems to be universally lacking (except on Airstreams) is good radii on the side-to-front and top junctions.