If you want evidence from a reasonably neutral observer, take Sandy Munro (himself an engineer who has worked on everything from cars to aeroplanes). He recently interviewed Elon, ostensibly about Tesla but the interview was in a meeting room at SpaceX. After the interview he was invited to a two hour design review meeting and was "blown away" at Elon's depth of involvement.
https://youtu.be/S1nc_chrNQk?t=370 (6:10 to 8:45)
I have no ideas about the depth of his technical knowledge at both companies, but the titles themselves don't hold much value when he gave them himself.
https://www.theverge.com/2021/5/7/22424592/tesla-elon-musk-a...
In this respect I'd imagine he's more akin to an overly excited tech geek who loves to obsess over the progress made by Andrej Karpathy and his team, but is otherwise leaving them alone to do their thing.
https://www.reddit.com/r/SpaceXLounge/comments/k1e0ta/eviden...
[0] https://www.reuters.com/article/us-space-bezos-idUSKBN1772ZQ