MSB has 10 platforms altogether as per IRI. 1,2,3 are terminals exclusive for TBM bound trains. 9 and 10 if we consider for MRTS, they still have 4,5,6,7 and 8. I believe one platform can be earmarked for MSB terminating express trains.
Some time back even the MS-PDY express was running as MSB-PDY express.
Its just thoughts. Practical difficulty we don't know.