I stopped using the entrance feeders after they sparked some massive robbing.
If the hole in your inner cover isn't the right size, you can improvise an easy inside feeder by putting a piece of screen the size of the box over the frames, setting your jar/s [upside down, with the holes in the lid] on the screen and putting an empty medium around it. a quart jar fits nicely inside a medium. Then your lids on top. You can check and change out jars quickly and safely without smoking or gear on because the screen keeps everybody down.
If you use an inner cover, make sure the notch is up so no bees can get in with your jars.