No. That, and the spawn rate isn't crazy to start with. It's using the same rate as vanilla does for pretty much everything.

That said, those damned Onions are evil and I hate them :)

Ah ok, could just be the amount of modded mobs that would otherwise spawn as onions or slimes in vanilla that I'm having trouble with. I'm getting swarmed by groups of flying, high-damage mobs on the starting planet and traders are being killed by them. I don't remember this being an issue in the past with Frackin but maybe I'm just misremembering.