Jackson–Owen lower-bound conjecture for realisation numbers of minimally 2-rigid graphs

Let $G$ be a minimally $2$-rigid graph with $n$ vertices, and let $c_2(G)$ denote its realisation number.

Jackson–Owen conjecture. Every minimally $2$-rigid graph $G$ with $n$ vertices satisfies

$$c_2(G) \geq 2^{n-3}.$$

This conjecture proposes an exponential lower bound for the number of realisations of minimally $2$-rigid graphs. The supplied text gives no information about whether the bound has been proved or disproved.