I had an idea for a mod with chain reactions. Cool overpowered tools to play with when you want to eradicate the natives and reduce time spent dealing with them because they are no longer a danger to you. Once you have spiders and nukes on mass production you can easily clear many square km of space, not still not very quickly. Artillery helps, but when you have artillery and insane range upgrades then why not go beyond op, for fun?
Weapon 1: Self replicating mines.
When a self replicating mine explodes it spawns a few new ones scattered around in the tiles around it.The new ones will take some time to arm so they won't instagib anything, but after a few attack your layers of mines will thicken a bit. After many attacks your mines will have helped you claim some more space. Eventually if the attacks keeps coming the mines will creep into their bases and very slowly take over all land covered by pollution (so that attacks are triggered).
Slow and steady. Starts out about as strong as regular mines but you don't have to replace them. Though there will be a lot of mines to pick up (for your bots hopefully) so you can build on the space. But it effectively creates a permanent slowly expanding perimeter that isolates you from the natives. Clearing the space from mines is maybe not that much faster than clearing it from natives though... depending on how dense the replication scattering is. And you might want to expand faster than the natural expansion of the mines, depending on the scattering distance as well.
Weapon 2: Self replicating distractor capsules
This one is fast, but for offense instead of defense.Replicator capsules (similar to distractor capsules) that live a short time and have a chance to spawn new replicator capsules around whatever they are shooting at.
I actually implemented this, but don't have access to it right now so if you are interested in testing then tell me and I'll update with an upload later....
They spawn faster than they decay, so they grow exponentially in numbers until everything within reach is dead. Since the new ones are spawned around the targets that were shot the cloud of replicators move and burns through big nests of natives faster and faster even if individual replicators don't move. The stronger and more numerous the enemy the faster they die because more targets means more time to build up numbers until eventually everything is instagibbed regardless of health or resitance (except complete immunity, in which case the replicators will turn on you and burn your pc instead of the natives).
To facilitate jumping further then just from spawner to spawner within a nest I added a small chance to spawn another type of replicators that die almost immediately when spawned but much longer range and higher chance to spawn new replicators. This enables replicators from nests to other nests and potentially clear huge areas. If enemy density is high enough (more than default death world though) they will spread until they have killed all enemies on the surface of Nauvis.
Replicators are OP, but they are not very strong on non-deathworlds. Small nests will mean that the nest will die before there's a big buildup of replicators and the rare long range replicators will not spawn and won't reach other nests.
I also tried a variant that spawned radars, solar panels, substations, big electric poles and maybe roboports and accumulators as well. Scattered randomly. It "worked" but wasn't very pretty or effective. Cool idea to have infrastructure already built on all that new real estate but probably not a good default option.