I think that is pretty much hitting it on the head.
And yes, he has looked tentative. But only at times. Overall, he has looked fine. People forget that in the Q, he was and thinks of himself as a facilitator. And he has set up some of the vets with glorious chances that have not been buried. And he has had some chances that have not been buried.
Appearing to be at times tentative is natural for a 19 year old rookie. It is expected. What seems silly is to heap this on the coach. Maybe a 19 year old rookie appears tentative because, well he is a 19 year old rookie in the NHL and is not somehow getting his talent coached out of him by his wicked coach?
It is still a small window, but young players tend to get better under Quinn. So, as they say, trust the process. And that can go for Lafreniere, for Kakko, and for the whole rebuild. Rome was not built in a day, despite some people's need for instant gratification or the delusions of grandeur that they have crafted around their team after spending most of a year in a lock down situation.