It sounds like he's doing really well! My ds was always a "learner"...but I definitely noticed that the things they did at school would spark an opportunity at home (made a "cave" in his bedroom for nocturnal animals after they discussed this in school for example).
My suggestion is to follow his passions and make learning fun. What my ds says he misses most now that he's in school full time is the hands-on things. Field trips, nature walks, science experiments - makes me half-wish we were homeschooling.
