My DS will be 7 months in a few days, and I'm in the process of cutting out DF as of now. He's currently at 9:00 consuming only about 3 ounces. Barely taking DF as well, I almost have to kinda rub his cheeks. I'm not sure if he'll make it through the night w/o it, but I don't want to take the chance.
Sounds like your LO is doing fine w/o DF or he may not want it. Plus if he's already rejecting it now, he's probably not hungry and wants to continue his sleep. When you add his third meal of solids you probably won't have to worry about DF at all. I know a lot of moms who don't DF, they just make sure he gets enough before going to bed.