Blue, I agree with iddee. If there is open space where the bees can reach, they will fill it with comb. They will comb up top feeders if there is space under them.
We don't know your location, but at least in the mid west USA, the bees have more than enough nectar sources outside. If there is nectar in your area, I would not feed this time of year.
If for some reason you have more than about 10mm of space between the top of your frames and the inner cover, they'll eventually burr that up. What you can do it use polyethylene sheet plastic to keep the burr comb from sticking to the inner cover if you want.