From the text in the game, it sounded like that changes to that setting wouldn’t take effect if changed later, but I’ll give it a shot.
I tried making a mod to blacklist a bunch of zombies, with the plan to manually remove the mode a day or two in, but that’s a pain.
I the sudden evolution wouldn’t be that big a problem, though. I’ll try that out when I get some time (like… sometime in the next couple of weeks, I hope) and let you know if it worked.