You don't have to go through the duty free. After security there is a door directly in front, half way along the wall of windows facing the apron in security east. It is labeled with a yellow sign for the terminal transfer bus. It takes you straight into the connector to the B/C gates bringing you out right next to the Aspire Despair dungeon - and is most handy if this is where you are going - possibly the only good thing about this lounge. You can then go upstairs/lift back to the main shop/food court area (the escalator only comes down from there) or you can rejoin the normal flow of passengers downstairs to the B gates bussing lounge.

Before the more recent link to the D gates was completed, and you had to go all round the houses to get there, this route was used in the opposite direction to bring passengers back down from the shops to walk along the back wall of the security hall (artfully segregated into a corridor by a row of benches...) before disappearing into a warren of passages at the west end. This meant that D gate passengers going direct to gate were sent on a very circuitous route passing back though the security hall they had previously been in a few minutes earlier after being forced through the duty free and shops...

There is also a door at the bottom of the escalators up to duty free, straight in front before you turn right, that takes you direct into the corridor to the A gates - skipping out the upstairs shops completely. However this requires an airside pass or well timed tailgating of a convoy of wheelchairs...