Holub–Lužar–Mihaliková–Mockovčiaková–Soták's large cycle product conjecture

Let $C_m$ and $C_n$ be cycles, and let $C_m\square C_n$ denote their Cartesian product.

Holub–Lužar–Mihaliková–Mockovčiaková–Soták's stronger conjecture. There exists a constant $c$ such that for all integers $m,n\geq c$,

$$\chi'_{st}(C_m\square C_n)=6.$$

This is presented in the survey as a stronger, lower-confidence version of the preceding cycle product conjecture. The known general bound is $6\leq\chi'_{st}(C_m\square C_n)\leq7$, and the asserted uniform eventual equality remains open.