S24 took Precalc in summer after Junior year, so he can take AP Calc AB in Senior year. It actually worked out very well. He got an A in the class, and he is currently getting an A in AP Calc. The Precalc got him prepare for SAT. Which he took right after the summer and got 780 in Math. Additionally, because of the extra summer course, he got 5 years of Math in high school which is recommended by Cal Poly. To OP, instead of taking Precalc in summer to accelerate Math, some others took Geometry in summer. Good Luck.