We agreed the following experiment would be interesting to both of us: We're sharing a ChatGPT Plus subscription, and I'm allowed to read the conversations he has with the model related to his learning projects. He's using it for general tech questions, but also for code analysis and code generation, bug-finding and so on.
It's been a mixed bag. On some level, his progress is faster and his productivity is higher than it would have been without the AI assistance. OTOH, the cost to this progress not having been hard-earned is pretty high, too: He takes a lot of AI-generated boilerplate for granted now without understanding it or the concepts behind it, so when the AI gets it wrong or forgets it, he is unable to notice what's missing. He also gets stumped/stuck often where he shouldn't - technically he's aware of all the constituent parts of the solution he needs, but he can't integrate the knowledge. Often he doesn't even try and just heads to ChatGPT, which can't help him, often because he doesn't know how to phrase the question correctly.
There's a lot of value to having done the legwork and having fought for every line of code and little bit of a solution that gets skipped over here in this style of the skill acquisition.
Edit: A few more details in later comment.