Hej,
seems like the biters are only removed if the mod is added the first time.
Nonetheless new generated chunks can have biters again.
Maybe on_chunk_charted https://lua-api.factorio.com/latest/events.html#on_chunk_charted could be used to keep the map free of biters.
This case happens if the mod is added, game saved and the mod is removed and readded later again as the init has already run?
I helped me out with:
script.on_event(defines.events.on_chunk_charted, function(event)
local surface = game.surfaces[event.surface_index]
for _, entity in pairs(surface.find_entities_filtered{area = event.area, force = "enemy"}) do
entity.destroy{raise_destroy=true}
end
end)
