Centaur has those gates on the inlane dividers and was designed so that a proper nudge will save the ball before it rolls to the drain. That's an example of working within the game. Not cheating. Hitting the machine to save the ball right before it hits the drain is something else to me, even setting aside the possibility of damaging stuff.
At home, on your game, do whatever. Play with the glass off and just pick it out of the outlane and set it back in the shooter lane. I'd just as soon working on legit nudging skills to prevent such drains when I'm not playing at homr.