I have been looking into this a lot as I am growing my channel by invite and request only to people I know will be likely to watch properly and subscribe. For example I am not sharing the channel at all with the general public, close friends and family just older subscribers off my main channel who request for the new one via Instagram. I think this way I am able to feed the algorithm my content and allow it to make a decision as to what happens next with it. It seems that these days sharing your channel with everyone and anyone actually can hurt your channels growth or seems likely to with how you have audience retention and video abandonment etc signally to YouTube whether your video should be pushed out to a larger pool of people.
I am seeing good audience retention compared to my main channel with a lot more subscribers.
What are your thoughts on this? Have you tried it? I am LOVING doing this as an experiment so far.