As a matter of interest regarding the Royal Brunei flight I just came back on. On the flight in to Heathrow, I had small packages ie 2x200ml bourbon and 2x200ml wine individually packed in separate bags, I had no trouble getting the unopened bags I had not used through Brunei.Then I got the whiskey $22 at Dubai and just walzt through customs (1ltre spirit allowance). But when I returned via Dubai (I had some byo packaged (2x each) up at Heathrow), and I went to duty free to get the Aussie 2.2 litres and they told me I would not get it through Brunei security, so no buy. When we went to board at Brunei my 2nd package from London was conviscated.
So Dubai was right, fortunately it was only about $28 worth.