Sampark Kranti Exp mostly run between Capital of Country & State.As it is there is one Maharashtra SKE is running twice a week & now this train you need Tri Weekly from Pune.
I suggest merge current running train with this & let Maharashtra SKE run daily from BDTS-Vasai Road-Panvel-Pune & after this as per your suggested route.
It will give connectivity for Mumbai western line with Pune directly.