Bader–Caprace–Lécureux's virtual simplicity conjecture for exotic Euclidean building lattices

Let $X$ be an irreducible, locally finite, exotic Euclidean building and let $\Gamma < \operatorname{Aut}(X)$ be a lattice. Bader–Caprace–Lécureux's conjecture. Then $\Gamma$ is virtually simple. This conjecture predicts that exotic lattices in irreducible locally finite Euclidean buildings have the strong normal-subgroup rigidity familiar from arithmetic lattices; the supplied text gives no resolution.