Grünbaum's rank-two self-dual configuration conjecture

A self-dual geometric configuration is a geometric configuration equipped with a duality mapping its points and lines to one another; its rank is the order of the self-duality. Grünbaum's conjecture. Every self-dual geometric configuration of rank $2$ has a realization such that its polar in a suitable circle is congruent to the original configuration. This concerns the relationship between combinatorial self-duality and geometric self-polarity; the source cites it in connection with the rank-two, reflexibly self-reciprocal configuration $\mathrm B(21_4)$, and no resolution is given here.