I have performed the KS test comparing two samples. My sample size is very large so the p value is very low even though the effect looks weak. I found a an explanation for the calculation of the effect size here (How do I calculate the effect size for the Kolmogorov-Smirnov Z statistic?) which suggests dividing the KS statistic by the $\sqrt\frac{n1*n2}{n1+n2}$. Are there any other methods for calculating effect size? I saw here (Robust effect sizes for 2 independent groups) that the KS statistics itself can be used directly as the effect size.
Secondly, is there a rule of thumb as to what is considered a big or small effect size in this case?