via TATA SER has a free run upto HWH JN Cabin as everything falls under it's jurisdiction, via DHN things are much messy as they have to contend with both ECR and ER...
Please note that it is also my personal opinion that the VB would have been a good success had it run via BKSC,DHN,ASN particularly considering it's proposed TT that is much faster than 12019/12020...