(14 Jan 2024, 1:09 pm)busmanT wrote I would guess that some of the people are from Pelican (the Yutong agent) assisting with familiarisation, some could be engineers and others from driver training.

They could be, but obviously the GNE "Systems Assistant" was on board judging by a post on Twitter. 

In your examples, surely it's a bit of a waste of an engineers time? They should know the bus is capable of doing the 21 (otherwise literally what is the point), and a run without passengers will yield limited useful data in comparison to the days of service work it will do. Familiarisation should be easily doable around the depot too. From the outside looking in it just looks like folk have fancied a day out, which is not very productive of them...