Finiteness-property conjecture for commutator subgroups of thick buildings

Let $d \in \mathbb{N}$ and let (\Delta_n)_{n \in \mathbb{N}) be a sequence of finite $d$-dimensional buildings whose thickness satisfies

$$\operatorname{th}(\Delta_n) \rightarrow \infty$$

as $n \rightarrow \infty$. For each building $\Delta_n$, let $W_{\Delta_n}$ be its right-angled Coxeter group and let $W_{\Delta_n}'$ be the commutator subgroup. The finiteness-property conjecture. Then, for all but finitely many $n$, there is a kernel of a map

$$W_{\Delta_n}'\to\mathbb{Z}$$

that is of type $\operatorname{F}_d$ but not of type $\operatorname{FP}_{d+1}$. This would give groups arising from sufficiently thick buildings with a sharp gap between finiteness properties $\operatorname{F}_d$ and $\operatorname{FP}_{d+1}$. The statement is presented as expected from the preceding spherical-subcomplex conjecture and is not resolved in the source.