Originally Posted by
fons
So I'm understanding that during the first leg (BNA -> EWR -> ZFV) there isn't much risk/repercussion in not taking the EWR-> ZFV leg and just staying in NYC.
It can get rather confusing, so completely understandable, but that above quoted part is incorrect: skipping EWR-ZFV in that scenario is NOT RECOMMENDED!!
There will be a high risk of the return portion being canceled!
From the Wiki:
"Booking Round Trip: XXX-EWR-ZFV, Skipping EWR-ZFV only - High-risk"