Jablan–Sazdanović conjecture on unknotting numbers of positive odd pretzel knots

Let $P(a_1,\dots,a_n)$ be the pretzel knot with $n$ odd and positive odd integers $a_1,\dots,a_n$, ordered so that $a_1\leq a_2\leq\dots\leq a_n$. Jablan–Sazdanović conjecture.

$$u(P(a_1,\dots,a_n))=\frac{\sum_{i=1}^{n-1}a_i}{2}.$$

This conjecture would determine the unknotting number for all pretzel knots with an odd number of positive odd parameters. The paper proves special cases, including families with parameters $(3,1,\dots,1,b)$ and $(3a,3b,3c)$, but the general assertion remains open.