Thanks again to all who have weighed in. There is so much good advice and collective expertise here that I hope this thread will remain active and be useful to others as well.
OK, as promised, I’m back with his YouScience results. The ‘recommended careers’ were mainly a list of every single flavor of engineer I’d ever heard of and several I hadn’t (photonics engineer? Had to look that one up!). For fun, some of the non-engineer recs were: archaeologist (he did love to dig in the dirt when he was little), medical scientist, and architect. But mostly: engineer after engineer after engineer.
Also, I second the rec for YouScience for any other parents following this thread. He has done several of these career-fit tests through school but said this one was completely different: much longer and more complex and with several challenging tests and puzzles. Well worth $30.
So, now we’re off to research LACs with engineering + merit $ + a decent-but-not-too-fast D3 team. (Fortunately, his sport is time-based so it’s relatively easy to figure out where he’d make the cut). And, of course, we’ll keep the club-sport-at-the-state-flagship plan as a backup.
One more question for the group in the meantime. I’m starting to think that another good path may be to send him to whichever LAC is the best combined ‘fit’ for a strong physics dept + merit $ + his sport and then tentatively plan on doing him engineering as his master’s. He’d have plenty of 529 $ left over for it if he chased serious merit, and that way he could have the full 4-year LAC experience with a well-rounded education and plenty of time to do his sport and a study abroad, etc. This is a kid who I recently caught reading Shakespeare ‘just for fun’. He would absolutely love a LAC education. And then he’d be making the decision about engineering as a 21 year old rather than as a 17 year old, yet could still graduate debt-free with a M.S. by age 23 (he’s very young for his grade). All of these seem like very good things!
So, to finally get to my question(s): How is a M.S. in engineering regarded? Do top firms recruit and ‘intern’ master’s students, or are they considered to be not as serious/smart as the B.S’s who went straight through? (Pardon my general bias against master’s degrees from the world of academia here 
).