If it's not I use at the time and the fridge is not running tape some plastic inside the vent door, remove before use.
Is there screen on the inside of the vent doors? If not rivet some aluminum window screen to the inside, ant water that gets past the louvers should hit the screen and run down and then out. Small gap in the gasket bottom behind the hinge should allow a drain path with hinge blocking inlet of water. Look at it, I'm not sure how newer doors are set up.