Conjecture that the two repetition ratios agree

For each minimum degree $\delta\geq4$, let $f(\delta)$ and $f'(\delta)$ denote the two repetition ratios defined in the paper for the diameter problem under the relevant clique- or chromatic-number condition.

Repetition-ratio conjecture. For every $\delta\geq4$,

$$f(\delta)=f'(\delta).$$

The conjecture is motivated by the exact computations for $\delta=4,5,6$, where the optimal repeatable graphs have equal chromatic and clique numbers; the supplied text gives no resolution for general $\delta$.