I don't see a problem- for the most part, the pellets are too big for them to eat, I've used them in the past and didn't have an issue. Just watch them, make sure they're not eating them, but you should be good.
We've used the pine pellet bedding from day 1 (our chicks were a day or so old I think when we got them). They are 10 days old now. It does get in the food so when it's time to refill the feeder, I dump what's left in it. I suppose I could sift out the pellets but I'm too lazy.