KVS uses ANA as it's data source. ANA don't even bother to check for availability on the 388, 77W and 345 - it will always return "not available" rather than "full" as soon as it sees those aircraft.

For any other SQ aircraft type, KVS/ANA is more reliable. There is always the chance that BD has access to extra inventory on 772/330/etc, but I don't know if we've much evidence for that either way.