This is interesting but what is it actually for? Cloning humans is not new but if we were to use this for replacing faulty organs, how does a newborn aged/size

This is interesting but what is it actually for? Cloning humans is not new but if we were to use this for replacing faulty organs, how does a newborn aged/sized organ help someone? Are they accelerating the growth of tissues and organs? If so, how do they slow the growth back down prior to transplant and also ensure whatever method used to accelerate the growth does not spread throughout the host? Or is this going to be a replacement for stem cell therapy to reduce the risk of tumors?