Gondwana from BSL serve same way for different class passenger, who dont have other option or too few for NDLS (like AK)!!
N option exist for BSL-NGP as direct connectivity along with availability, as the stretch is small with different Quota earmarked for both stations!!
Simply, one who need to travel end to end, will not opt this train & choice always rely on passenger! As for run time, the train's purpose isnt run but connectivity & still with that run, it justifies its SF Status!!