Just to follow up, for anyone mad enough to consider a back-to-back at SEZ, I did it this morning without any problems.

Following C-W-S’s advice above, I ensured I was first off the aircraft and proceeded to immigration.

Immigration was completely deserted as no other aircraft had recently arrived, at least from an international destination, (My BA service had arrived one hour late due to an ATC delay).

There I was directed to a transit channel, which involved me doubling back on myself and walking back towards the aircraft.

The best course of action after walking down the stairs from the aircraft would be to proceed to the terminal building, turn right (instead of left towards immigration) and follow signs for transit. There was a locked door, which someone opened soon after I knocked.

A member of security staff was called and within 2-3 minutes my hand baggage had been screened and I was directed upstairs to the lounge.

From leaving the aircraft to being in the lounge took around 8 minutes, which could have been 5 if I had proceeded immediately to the transit channel.

I had my return boarding pass in hand and despite being a little perplexed, staff were friendly and pleasant during my short stay at SEZ.

Boarding was a shambolic free-for-all with no group system even attempted. Departure was around 50 minutes late so turnaround was accomplished in around 1hr40, which would be difficult to improve on unless loads were very light.

Talking of loads, Club World was well subscribed in both directions with probably around 5 unoccupied seats on the outbound and 10 on the return.

The 787-900 is a great aircraft to fly on for an itinerary like this. I had 7E in CW on the outbound and 7K on the return-both superb seats with great privacy and direct aisle access (to both aisles in the case of 7E).

So in summary I would rate SEZ as excellent for a B2B, as long as HBO and with the SEZ-LHR printed in advance, but most ‘normal’ people would do well to spend at least a few days on what looked like a spectacular island.