I am not suggesting SMET MAS via Renigunta. I am suggesting SMET MAS via YPR bypass with RSA as MAS UBL via Renigunta. This can give triweekly UBL MAS and triweekly SMET MAS.
I suggested Tambaram because SR can always reject train from SWR saying PF problem at MAS. To avoid, train can go to TBM or Chengalpattu either via Egmore or via Kanchipuram.
Point is that night train from UBL or SMET should reach Chennai before 8 AM.