PS - why would there be more driving time on tests -
The gear change exersise only took around four or five minutes at the most so it makes little difference to the overall test time wise.
I could see the point of it when I took my test (1992) as DDC was still a requirement and even though synchro was common on training vehicles you had to show that when you were out in the real world with 38 ton on drum brakes you weren’t going to fly down a hill desperately trying to crunch into something other than neutral! Today we have twice the power, synchromesh as standard and better brakes so a fluffed gearchange is less likely to get you into trouble.
I’d argue that with a modern synchro box there is no longer any skill required to actually make the change but you still need to know which gear to use. On that basis it’s pointless trundling down a quiet road working through the box and better to concentrate on the decisions made in real driving.