I personally would not subject accelerate for reading without commensurate writing skills (both penmanship and stamina). As you get into the higher grades, decoding is less important and written interpretation skills are more important.
Also, IME, reading skills for good readers tend to grow by more than a year at a time, so challenging placement at the beginning of the year won't be a good fit even a few months later.
First was a trial for my DD, too. They were really limited in what they were allowed to check out of the library or read in class. I sent DD with books from home, and that helped some.
Her math was good enough to do a full skip of second, and the third teachers were much more willing for the kids to advance through books at their own pace. Fourth is starting to chafe a bit, but DD kind of understands that the point of fourth grade reading is interpretation, not reading the hardest or most interesting books you can.
