Allcock's Bimonster covering conjecture

A 13-dimensional complex ball quotient is obtained from the Allcock lattice construction, with $X$ denoting the corresponding ball quotient and $X^{\rm sg}$ its singular or special-locus pair. Allcock's conjecture. The universal reflection Galois group of the pair $(X,X^{\rm sg})$ is isomorphic to the Bimonster

$${\mathbf M}\wr\mu_2=({\mathbf M}\times{\mathbf M})\rtimes\mu_2,$$

where ${\mathbf M}$ is the Monster, the largest sporadic simple group. This is the precise covering-group formulation of Allcock's proposal for the natural Bimonster covering of the 13-dimensional ball quotient; the supplied text does not state whether the conjecture has been resolved.