I adore this mod, a lot more than I expected to honestly, it has very much became one of my favorite enemy mods out there just from how something so seemingly simple has made me change up my playstyle so much. However, I do have one thing on my mind that I would love to see from this, which is the ability to set a multiplier for how many zombies are spawned. Mostly out of masochism for my CPU, but I would love to be able to flick it to 2x or something and just see how long my setup is able to keep up with ammunition costs and all that.
No idea how difficult that would be to implement, but figured it was worth a shot to ask, and regardless of it comes about or not, I still wanted to say that I love the mod and thanks for putting it together! :D

Appreciate the feedback :)
I've just started playing Factorio again so my interest in modding is coming back.
There is a setting to have more Zombies around the spawners, but I didn't think of allowing customisable attack waves. I'll look into it!

Awesome! Thanks so much, I wish you the best of luck with the factorio vibes and modding :D

New version up. I made the setting adjust the amount of pollution required to spawn a zombie into the attack wave. It defaults to 20, so if you set it to 40 for example that halves the pollution required and should effectively double the speed that an attack wave is formed.
Hopefully that will do what you want, if not let me know and I can try something else. You can also set it up to 200 which should be 10 times more!

Yessss, this was exactly what I was looking for! Thank you so much :DD