SilkAir is not Singapore Airlines' low cost subsidiary. Tiger Airways is SQ's low cost short haul subsidiary and Scoot is SQ's low cost long haul subsidiary.
SilkAir is Singapore Airlines' regional airline, e.g. the part of SQ than operates the narrow bodies (similar as to what KA is to CX). There's nothing low cost about them. They have a J class and serve a full meal even of very short flights.
Enjoying the report. Looking forward to the rest.