Could you clarify what you are trying to achieve with this comment? I work in a related field and talk to stem cell/organoid growers from time to time.

It is in fact hard to grow brain organoids from stem cells; this is still very much a thing that requires expert hands and minds to do effectively.

Unfortunately I'm not able to validate the second point (that the results of the research made a new technique for growing brain cells) because the paper is very technical in ways I'm not an expert.