Maybe ship harvesters should have diminishing returns implemented. So that they slowly get less and less resources the longer they harvest.
It could be implemented so that it creates a daily limit to the amount of resources that can be harvested. This limit should probably be per resource per world, so we can't just use multiple ships.
It could be implemented so that it creates a daily limit to the amount of resources that can be harvested. This limit should probably be per resource per world, so we can't just use multiple ships.