I don’t think we have a great track record at fully understanding these complex biological systems well enough to engineer life.
theres 8 billion of us because of farming. most of the farmers dont really know how it all works.
woudln't it be cool to make nodules and go drop them in barren parts of the ocean and then they become seeded?
which was true 10,000 years ago before humans even know what cells or photosynthesis was. people had farms then.
so the point is, even without a genuine understanding, if the causal relationship between seeding parts of the ocean and the desired result is achieved, then an understanding wouldnt be necessary.