Children have no Default Mode Network (DMN) associated with self-referential thought in the early years of their lives. It develops with age. And so the Lidcombe program works for as long as the DMN is still undeveloped for them to think on their own and outside the parent's domain of influence. The parent can't forever be there to provide feedback either. Who does the authority of getting feedback from transfer unto then? To everyone else? Some will be nice, some will be bullies, others vindictive, and whatever. That's a bunch of mixed signals. In my opinion, the Lidcombe program is the worst disservice a parent can do to their child. It's horrendous. If my child stutters, I will look to develop their resilience, self-reliance, and across as many domains as I can so that they grow with an internalized sense of identity. If I condition my child to externalize it to myself or my wife, they will transfer it to anyone present when we are not there. Why? Because they are conditioned to externalize and become incapable of individuating themselves. It's detrimental in childhood and ineffective as we age is how I would put it. So no answers to give on how it can improve. If it was for me, I'd let it die out. The perfect approach is something that mimics the patterns of spontaneous recovery in stutterers, which this definitely isn't.