Conjecture on even pretzel knots with maximal nonorientable concordance genus

Let $n\ge 3$, and let an even $n$-stranded pretzel knot be a pretzel knot $K=P(a_1,\dots,a_n)$ with even parameters in the sense used for pretzel knots. Write $\gamma_c(K)$ for the nonorientable concordance genus of $K$. Pretzel-knot concordance genus conjecture. For every $n\ge 3$ there exist infinitely many even $n$-stranded pretzel knots $K=P(a_1,\dots,a_n)$ with

$$\gamma_c(K)=n-1.$$

The preceding results establish the assertion for $n=3$ and $n=4$ using rational Witt spans; the conjecture asks for analogous infinite families for every number of strands at least three.