If Varanasi has to be pampered with VB trains the better option would be:
** A VB from Lucknow-Varanasi-DDUpadhyayJn-Gaya-Dhanbad-Asansol-Durgapur-HWH 950km could be a better option. 2024 when a major part of the route shall be 160kmph & rest for 130kmph.
** However a weekly/biweekly/triweekly VB with ac sleeper coaches can be introduced between Varanasi & Mumbai/ Bangalore/ Hyderabad/ Chennai/ Ahmedabad etc.