I might suggest that you look at all the schools near L’ville. Two are primarily day with boarding (mostly international) but have great learning support - Hun and Pennington. (Hun is better with visual processing issues and Pennington is known for supporting kids with auditory processing issues.) George is about 20 minutes west and Peddie is about 20 minutes east. Two different vibes but both excellent schools. Both have reputations for welcoming different types of learners. George is very strong at STEM and doesn’t seem worried about “uneven” kids. You’d be able to visit when you visit your D (soon, non-Covid). Hill isn’t so far either.
One thing I would toss into the search is finding the structure that would work best for your son. Personally, I don’t think it’s unusual for a 7th grade boy to do work just to get it done. I wouldn’t characterize him as lazy for this!
Schools differ in how much freedom they provide around study halls, etc. Some kids abhor the structure and even rebel against it while others get nothing done without it. Most kids work it out one way or another, but for some, this is critical.