No need of extending premium trains of Nagpur like GR and DURONTO etc to anywhere and even no one demanded for the same. About Vidarbha & Maharashtra so Nagpur already compensated with NGP KOP express and NGP CSTM Sewagram/Nandigram and still enjoying quota of 12105/06 and 11039/40.Even a ticket with WL-5 won't get confirmed in Maharashtra express from Gondia To Pune. The trains you have mentioned may be extended sooner or later(most probably after completion of 3rd line work b/w DURG-G-NGP)but it depends on the several factors like Rake availability For BJU G BJU epxress for its extension till Nagpur/Ajni ,Slot availability etc...