What you’ll find is, that although the penalty for having one of these devices is relatively mild, DVSA take it as a signal that the fleet the truck belongs to is ill-maintained, and the boss is bent. The operating centre then gets an uninvited visit from the hi-viz clad ones and the inevitable invitation to the TC’s office is triggered.
As for the Gloucestershire case…the haulier concerned elected not to have legal representation during the hearing, so I suspect the appeal is just a waste of money that would have been better spent on having a lawyer present at the PI.
‘Not knowing’ about AdBlue is a bit of a feeble excuse…it suggests no one has bothered to find anything out about the truck at all since it was purchased. And transport managers are supposed to keep themselves up-to-date on legislation etc…it’s hard to find a truck magazine published in the last 10 years that doesn’t have either an article mentioning AdBlue/SCR or an advert for AdBlue.