OK, I finally did it. I'd had misgivings about jumping out of the system, but it seemed a faster way into town, and possibly marginally cheaper.
Surprised to find someone actually martialing divers and allocating them to passengers braving the the turnstiles. This was at the far end of the curb - with hindsight it might be better to use the near end, closer to TG's check-in.
Driver agreed to meter, and only took a little more convincing after we set off. But then headed on local roads to find a garage to refuel, removing any time-saving benefit and putting B20+ waiting time on the clock.
Killing time while waiting, I removed the postcard covering his driver ID

. Benefit of being front seat passenger. It was confrontational, I know, to then take a photo of his ID - but I sensed potential for skullduggery. And I was pissed off: so was the diver.
Once on the highway couldn't help notice the erratic meter jumps, which seemed to coincide with a nervous tick of the driver. I did a pantomime double-take of the reading, he yelled a bit, the clicks became calmer.
All in all, I think i'll stick to the regular queue and leave the departure level to locals and experts!