Nice explanation Bro ,Another reason is Godavari arrival before GT at BZA 2305/2315 ,so it has to OT GT anywhere between WL to Rayanpadu.
Once GT departs from Bza ,it has very agressive run.Even y day if u see Godavari covered 351 km in 5.13 hours ( Bza- vskp ) and GT took 5.45 to cover 430 km.Left alone ,GT goes great gun .but nothing comes close to TN some time it takes 5.15 hrs between bza - mas even pre Covid days and kept waiting at outer