not only will they fill the holes, but they will use that middle structure to attach comb to the next frame. you will have to cut it apart for your inspections. :-D
nothing wrong with your thinking, and it will just cost you a little more work, and some brood to try.
bees have no problem getting around the hive. you can open a wall space and find comb 5 feet long and stacked in 3 or 4 deep. they manage to transit the comb, raise brood, and store, without problem.