Extending to Nepal is possible; extending to Tibet is not. IIRC, Lhasa lies in Autonomous region of PRC; thus unless India wants to instigate a war just for laying a rail track, it is impossible.
Yes you are right the present Anga exp along with Jasidh express can be made a triweekly from BGP and also MFP weekly to Biweekly , 2 days from Gaya Dhanbad Asansol and giving a separate slot will cater the needs of the region.
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