The Authority of the Celestial Supreme is very powerful so the increase in productivity of Origin essence by the tree father is double that of Legion-1. Now they have a combined production of 30 origin essence per Origin cycle. It is a lot for a weak origin god but it is nowhere near the infinite amount they need.
On the bright side, the tree father also doesn't need to dilute Origin essence to make Origin energy. He can make it directly as a by-product of making Origin essence. He is also not the only one changed by the development. The inner world changed too. It became stronger and self-sustaining which made his world devour ability became stronger.
The best change is that they are finally able to use cosmic energy. The tree father can use it to strengthen his domain. That means the inner world can grow stronger. It is an underwhelming change but it is welcomed because they couldn't use cosmic energy for anything other than reinforcing concepts. It just didn't listen to them.
