With 130kph MPS in HWH BZA section, reduction of the big slack in GNT GTL section, avoiding slip attachment and detachment at GTL, shifting LC from GTL to UBL and removing some halts like DVD (since it goes to VSKP now) atleast 2 hours speed up is possible which would be enough to raise average speed to 55kph for SF conversion.
Also pre covid when LD HPT route was not fully double line and GNT GTL was a single line totally it used to do HWH VSG at 53 kph average and VSG HWH at 54 kph average speed.