QFT
My education was strictly by the book, including getting to read when I'd finished my work. It took me until I was in my late 20's to learn how to work hard at something and I still have bad focus or determination.
More important than anything else, a child needs to learn how to work at something, how not to give up if something's hard.
That's what worries me--I was that kid, too. I sailed through AP classes in high school, then almost failed out of my first year in college (squeaked by with a 2.0). I still have issues with focus and planning and not-procrastinating.
DD7's teacher has a list of things they can do if they finish early. Every day, DD7 finishes her homework/busywork in class, reads books, and makes craft projects, all because she finishes early.