More of a "feature" than a "quirk" that actually facilitates quicker connections. Most airports across Asia require you to go to a central security checkpoint, and queue with everyone doing a intl->intl connection (no distinction for those with flights departing in <1 hr vs those departing in 4 hrs time). Whereas for SQ at SIN (and any carriers operating from T1/2/3) you don't have this choke point, instead only do security at the gate where most of the time the only queue you have to face is with others travelling on your flight.


You must be unlucky, I've flown SIN-Australia over 100 times in the last 16 years and can't recall a single instance of this happening. Except in T4 for Jetstar flights, unnecessary as gate based security takes care of this quirk (vs say BKK, HKG, DPS etc where the check is common). But you are right that buying DF booze at AMS will end up in the DF being confiscated, and you can't buy at SIN with <90 to departure for Australian flights.