[InfiniteRand]

I remember observing a 2nd grade classroom (when I was considering being a teacher) and seeing the teacher yell at a kid for going to fast in a practice test, same thing happened to me in 2nd grade. In middle school if I finished in-class work early, I would pull out a book or two, which might be tough to put down when the teacher moved to the next topic. So I think it's pretty common for students going too fast to butt heads with teachers (fortunately most of my teachers liked me for other reasons, which meant the butt-ing head moments did not build and tensions got dispersed)

That being said, the recommendation I heard when I was studying education was to offer enrichment activities. Which allows smart kids to do their own thing without going in front of the rest of the class in the normal material (so that you do not need full-on tracking and class separation). I generally like that recommendation, although it is not a cure-all. I may be biased since this fit my learning style well well since my academic behavior was chronically inconsistent at times (on-set of mental illness), and the enrichment activities often counted for extra credit which helped me make up for times when I was underperforming.

More generally I think letting smart kids build up a cushion of extra credit takes the edge off of the "always-need-to-be-perfect" pressure smart kids often feel.