Panvel does not has any infrastructure for origination/termination of Mail/Express trains. Moreover recently in 2-3 years only it got adequate ticket counters too (New Panvel got its ticket counters only in year 2012). During peak hours people crossing from Old Panvel to New Panvel is nightmare through FOB if any short distance Mail/Passenger trains arrive, in short this station handles too much crowd (local crowd) compared to it's given amenities, so I would always say first construct another FOB & better infrastructure for train maintenance before pushing for new demands!
Thanks...