The congestion problem is more in BZA-VSKP sector than BZA-MAS and north-bound traffic at BZA is managed well due to PF arrangements. And BZA-GDR 3rd line has been commissioned, which can further improve things.
Your proposal is also useful, once the proposed port corridor in AP is sanctioned. A connection between MTM-BPT bypassing BZA is part of the plan.