The elliptic braid-group presentation conjecture

Let $R$ be an elliptic root system, with underlying affine part $R_a$. Let $\tilde{W}(R)$ be its extended Weyl group, let $\tilde{c}$ be a hyperbolic Coxeter element satisfying

$$\tilde{W}(R)/\langle\tilde{c}\rangle \simeq W(R),$$

and let $\mathrm{\tilde{A}r}(R_a)$ denote the group appearing in the affine presentation. Elliptic braid-group presentation conjecture. For every elliptic root system $R$,

$$\mathrm{\tilde{A}r}(R_a)/\langle\tilde{c}\rangle \simeq \mathrm{Br}(W(R)).$$

The claim proposes that the presentation phenomenon established in type $A$ persists for arbitrary elliptic root systems after central evaluation. A conceptual proof is not known, according to the source.