Not useful if passing directly through and onto SYD, but if on a stopover and if it is financially worthwhile - or even if you just fancy using the service anyway - a pragmatic workaround to this might be to use the JetQuay service at Singapore.

You are met at the aircraft door by cart and they collect your luggage for you and whilst they do you are taken to the CIP terminal to wait for your luggage to be delivered directly to a limmo which takes you into town. Whilst there is an immigration officer they do not appear to have customs officers and I have never been asked to declare anything carried on board. On one occasion I had psyched myself up to pay an awful amount on a couple of boxes of Cuban cigars I took as a gift but was never asked. As it happens the JetQuay service whilst expensive was less than the tax. They have also done some "personal shopping" whilst we were waiting ie they took our passport and cash and went off and bought our booze and put it directly into the limmo trunk for us without any further payments or declarations.