Baby supers are fine as long as they're small enough. They can get out of shallow feeding dishes tho and it's not good to have them wandering the cage.
my hatchlings eat 1" supers right off the bat. I've had hatchlings as small as 8-10 grams take a full grown 2" superworm before. (At that stage it only takes one). I hear alot of people talk about this subject and its really not necessary to feed smaller items as they are fully capable of eating more than most people think. In my opinion feeding smaller worms in a higher numbers is less effective due to the amount of exoskeleton consumed vs one or 2 larger worms with alot more of the good stuff. Just my two cents though...