The dripping from the vent only occurs when I'm using my Bradley in cold weather. The problem I have when that happens is due to the warm moist air escaping through the vent condenses when it hits the colder air. This condensation builds up and it drips down on the food. Since the bowl is inside the cabinet, there will be no condensation on the outside of the bowl. So the drippings will gather in the bowl, and will/may be turned into steam again, and start the process over. Also I believe the vent bowl is removable.
The vent bowl should work. If you do a search, you will see many members used different items to resolved this problem, prior to Bradley actually doing something about it. During colder weather, I place an empty rack on the top self, and use either cheese cloth or a coffee filter under the vent to catch the dripping. As mentioned earlier, I only had to do this during the winter, and cold autumn days. Some members would use a small disposable pie pan.