[Vikesrock]

For the sake of discussion, if this were legal what advantage do you gain for the added complexity? Is it worth it?

The only scenario I see this being useful in would be climbing up the bump at an angle. For this fringe case that can be potentially avoided by the drivers I don't see the added complexity as being worth it.

Regarding the legality, as Al mentioned above the Frame Perimeter restrictions would apply. You would need a fixed, non-pivoting frame perimeter structure, a separate structure for the wheels that articulates the way you want and some type of spring or gas shock to connect them.