yeah, bad idea. There are cooling lines throughout the freezer box (it's actually how the whole fridge works, there's no actual cooling lines in the fridge section, just the freezer, and that cools the whole thing.
You may be able to cut away some of the plastic from the top of the fridge section and fit the fermentor in that way. Or you can switch to a blowoff tub that would be lower than an airlock. But don't cut the partition