Beresnevich–Velani's Hausdorff-measure Duffin–Schaeffer conjecture

Let $\psi:\mathbb{N}\to\mathbb{R}$ be non-negative, let $W(\psi)$ be the associated limsup set of reduced rational approximation intervals, and let $f:[0,\infty)\to[0,\infty)$ be a dimension function. Write $\mathcal H^f$ for the corresponding Hausdorff $f$-measure on $\mathbb{R}/\mathbb{Z}$. Beresnevich–Velani's conjecture. If $r^{-1}f(r)$ is monotonic and

$$\sum_{n=1}^{\infty}f\left(\frac{\psi(n)}{n}\right)\varphi(n)=\infty,$$

then

$$\mathcal H^f(W(\psi))=\mathcal H^f(\mathbb{R}/\mathbb{Z}).$$

The paper states that this conjecture is equivalent to the classical Duffin–Schaeffer conjecture via the Mass Transference Principle, and it was open in the source.