Are you referring to ERS -SBC 12678 ? There was some attempt and push few years back to get this done but it was rejected. MYS MP was trying a lot for that. Instead Chennai-SBC got extended which almost had similar timings. Alternatively KCVL-SBC overnite train (16315/16316) got extended to Mys which was felt a better option as it also connected TVC to Mys