Was just thinking of this.. If SWR wants to keep an RSA for Karnataka express, then:
1) Get LHB rake for 12658 and break the RSA of 12658 and 12628.
2) Introduce a new daily night train b/w SBC and MAS (timings can be SBC 23:40 MAS 6 AM or something like that and return MAS dep 22:20 (maybe just behind Cheran) and SBC Arr 4:30 or something. THis train can be given RSA with KK Express.
Feedback...
more... please.. (This can be a second proper daily night train between SBC and MAS)