Does he have a lot of solids when he eats? Also, does he wake at all in the middle of the night?
6.5 months might be too young to eliminate the DF, but it depends on the child. The thought is if you are slowly eliminating the ounces, then they start making up for it elsewhere. Each child would resolve this differently. Some babies will start eating more else where without the cluster feed if you eliminate the ounces slowly. Others will need the clusterfeed, and then as their bellies get bigger, the cluster feeds start consolidating as well.
So, not to give you a wishy washy answer, but it somewhat depends on your child.