Thanks to datatags on the Github there is now configuration file, which allows to customize plugin behaviour. Currently there is only one option to change, but I hope I'll add extra functionality in the near future. You can set percentage chance for the creeper to be Confetti Creeper, this value is by default 100%, so every creeper will explode into unharmful confetti. You can change it to any value you want between 0(where plugin is useless, all the creepers destroy terrain) and 100(all the creepers are non-destructive). Thanks again to datatags!