The wheel-graph adjacency-polytope volume conjecture

Let $W_N=K_1\vee C_N$ be the wheel graph obtained by joining a single vertex to the cycle $C_N$, and let $\operatorname{NVol}(\nabla^{\operatorname{PQ}}_{W_N})$ denote the normalized volume of its type-PQ adjacency polytope. Wheel-graph volume conjecture. For all $N\geq 3$,

$$\operatorname{NVol}(\nabla^{\operatorname{PQ}}_{W_N})=3^N-2^N+1.$$

This gives a conjectural closed formula for the normalized volumes of wheel graphs, a planar class that is not generally outerplanar. The source provides no proof or resolution, so the conjecture remains open.