After viewing multiple videos online, it appears the orbit that feeds into the right inlane should never drain in the outlane. However, mine does this quite often. Admittedly, I am a bit obsessed with getting this correct because a huge strategy to starting multiball is to spot letters via the right inlane.
I believe it has something to do with the one-way gate that is close to the shooter lane. I would be incredibly greatful if someone could take a couple pictures of this gate so I can see if mine is installed correctly.