A lot of airports now (note not all, but a fair few - US is still not one of them) will let LAGs under 100mL slide (that is, not ping them if they are in your hand luggage and haven't been separately presented for scanning). However, anything larger will generally get flagged.

On manual hand baggage searches before boarding flights to Aus, all I can say is I really appreciate the Emirates First Concourse A lounge and it's in-lounge boarding gates, so your bag contents don't have to be inspected before all and sundry. In fact, I find the First lounge (at DXB Concourse A) makes boarding far better than what I go through at SIN.