Alexeev–Borisov boundedness conjecture for delta-log-canonical weak log Fano varieties

Let $\delta>0$ be a real number. A delta-log-canonical weak log Fano pair is a pair $(X/\operatorname{pt.},B)$ of dimension $d$ that is $\delta$-log canonical and weak log Fano, where $B$ is a boundary. Alexeev–Borisov boundedness conjecture. The varieties $X$ for which $(X/\operatorname{pt.},B)$ is a $d$-dimensional $\delta$-log-canonical weak log Fano pair form a bounded family.

The paper attributes this conjecture to Alexeev, A. Borisov, and L. Borisov, and states that in characteristic zero its dimension-$3$ case implies termination of sequences of log flips starting with four-dimensional log canonical pairs of nonnegative Kodaira dimension. The supplied text does not state whether the conjecture had been resolved.