Malgudi Express: From the pages of RK Narayan to the railway tracks of Mysore. - Vageesh

It's not exactly the same situation. RC and Amaravati carry the through coaches in both directions.
With the exception of a very few trains like 11047/48 (most of which are introduced solely for carrying the through coaches), IR typically does not run Up and down trains with different coach compositions (not the order of arrangement but addition of through coaches etc) or run trains with through coaches in one direction only.
As of now, the return journey will be through RC only as...
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it is the only one that connects to Goa express and gives an overnight journey. If they use Siddhaganga or Viswamanava, the through coaches will be in one direction only, which is something IR avoids as much as possible.
Also in case of Siddhaganga, if additional coaches are attached from UBL due to demand (these will be from MYS base), they will have to be detached at SBC to attach the through coaches. They will have to figure out other arrangements to send these coaches back to MYS/UBL.