Don’t assume Pre-Calc to Calc BC, even for strong students. We had one local HS that would not, under any circumstance, allow a student to skip Calc AB, but a second one had a standard track from Pre-calc to Calc BC - only kids who didn’t flourish in Pre-calc went into Calc AB first. I would definitely ask the schools directly.
Also, regarding like-minded students, it would be good to find out the range of math/STEM clubs offered and how active they are. Some strong math students have no interest in competition math, but for the ones who like it, the clubs often provide a way to socialize outside of the classroom and forge friendships, especially if the clubs are student-led and not faculty-led.