This has two issues:
1- requires speeding up of IND-NGP segment
2- VB trains, IMO, are already suffering with lack of maintenance (especially cleaning part). Extending the run of a rake will likely make it worse.
I...
more... took two VB trains last month and neither were clean/maintained as they should be, and this was in executive class in both.
Had the same issue with Tejas Express (I had high hopes on that one) from Mumbai to Madgaon but lavatory started dirty from Mumbai and was cleaned in Ratnagiri which is the only station with 2 minute stoppage on that route.
Since then, I've been told Shatabdi rakes are maintained better than VB since their turn arounds tend to be tighter and they usually stop for 2 minutes at most stations (so in between clean up is an issue).