What I've seen so far is sometimes when biters die an acid shot is fired towards what killed em, then regardless of whether it hits periodically medium biters spawn on that object... Idk if that's your mod or not, but I didn't notice it until I got it
Oh in the description you said it can scale infinitely or something like that, I didn't know if you meant literally or that it happened in the background. My bad
Oh! This mod simulates evolution > 1 by nerfing player damage, however this is done entirely based on time and is not actually tied to evolution. The types of biters (and their behaviors) are unrelated to this damage scaling factor.