After building a prototype of the twin-goose-neck rear wing and diffuser setup, it looked like it could develop even further. Also, the flat floor left quite a bit of unused room under the battery boxes which could be utilized for underfloor tunnels.
The tunnel underfloor will bring the center of pressure further forward and should drive more underbody flow to the rear diffuser.
The single-strut gooseneck wing support's supporting side-plates form a very rigid triangle against the Traxxas rear bulkhead. The bulkhead is being whittled down to the barest minimum and will allow a very low and sleek rear bodywork deck to flow more air through the wing. The single support will rely on the wing's endplates for some strength and stability... it could also turn out to be too fragile but I won't know until I try it.