Wow, sorry then I believe I have completely misunderstood what this mod does. After getting crushed I've come back to the mod description and read quickly "Each spawner also will spawn biters based on evo factor.", so I thought it just meant the overall biter spawning rate would be increased. But now I understand this part just means spawners will split when you destroy them, right ?
Though, there's definitely something strange, as I'm 90% sure the mod makes more biters spawn near spawners (just as if I was polluting 4x more) and it ceases when I disable it. I indeed have Rampant installed., but I don't think it alone is the problem because after disabling only your mod the number of attacks went back to normal.
Thanks for your quick answer, now I will try to confirm the issue again this week to make sure it wasn't just placebo :D