First, it's not necessary, and second, it's not technically possible as the TAT is very low. Another rake will be needed.

Another problem will be that Mahabodhi and Vikramshila run back to back in the NCR almost all the time. Very often, 12368 overtakes 12398. Both depart from DDU on different routes, and even if this extension happens with an extra rake, from KIUL again, 12368 and 12398 will run together back to back till BGP.

The rake of 12398 will not be able to return to the same day as it reaches BGP by 8:30 am as there is no TAT, so maybe another rake will be sent from Gaya that day for NDLS and the MB rake will remain at BGP till the next day. BGP keeps Anga in their yard for a long time, and if another train takes up space in the yard, BGP might refuse.

Again, Mahabodhi is a dedicated train from Gaya and this extension shouldn't happen.