ACC conjecture for $a$-lc thresholds of exceptional singularities

Let $d$ be a positive integer, $a$ a non-negative real number, and $\Gamma$ a DCC set. For an lc germ $(X\ni x,B)$ and an $\mathbb{R}$-Cartier divisor $D$, let $a\text{-}\operatorname{lct}(X\ni x,B;D)$ denote the $a$-lc threshold. ACC conjecture for $a$-lc thresholds. The set

$$\{a\text{-}\operatorname{lct}(X\ni x,B;D)\mid \dim X=d,\ (X\ni x,B)\text{ is lc},\ B,D\in\Gamma\}$$

is an ACC set. The conjecture includes the usual log canonical and canonical thresholds when $a=0$ and $a=1$; the source states that it remains open in general when $\dim X\geq3$.