Road: Stabilizers. We tested the torque exacted on a vertically-mounted 12V car outlet and finalized the stabilizer design required to ensure that Road fits firmly and snugly.

Wall: Package expansion. It turned out that, even using GaN, there were severe space constraints for Wall. Much of the interior is taken up by the tip mechanism and wall prongs leaving precious little for charging circuitry. The system is based on a standard width across all products, so that could not be increased — hence we made the decision to expand the depth, front to back, which far more than doubles the total space available for circuit boards in current and future models. As an added benefit, future products will also be able to use a variant of this form factor.