What Goethe actually wrote was: “Everything is leaf, and with this simplicity, the greatest complexity is possible”.
If you want a better understanding of what he was on about... you could try here or here... or maybe read my previous post here.
From simplicity the greatest complexity arises... bacteria to multicellular organisms... I think there is an evoluntion toward complexity... mycelial networks, neural networks, cultural networks... but the complexity isn't paramount in the individual or one species (a clever human, the human species) - no: the value lies in the complexity of the whole. Gaia. While one species, for the betterment of its complexity, decomplexifies the rest of the world, it is antagonistic to the process. It is a form of anti-evolution.
I am in the midst of reading the links you provide. It's a good time of year to be thinking about and looking at new leaves. It's good to return to this. I also read the novel Everything the Light Touches and I'm glad you are following up more with Goethe.