Wherever you go, whatever company it is, just do what you’ve got to do before leaving the yard, and never let them push you. Don’t even break it down to them. Just tell them “it’s what I need to do”, and deflect further interrogation, or play on the health and safety aspect, or ask them if they’ve ever “driven an artic”. Whatever you do, don’t justify yourself more than you need to. My pet hate is being pushed.
Personally I take approx 45 minutes from collecting keys to leaving yard (as do several others), and would not compromise on any of it. This nonsense about “we need you out of the yard in 15 minutes” needs to be ignored. Just ignore the muppets, and do what you’ve got to do. What’s the worst that can happen? In my experience the most stubborn drivers never get sacked, they just eventually get left alone, or even promoted! Some are continually called into the office, but never seem to get sacked.
Just see it as a big bloody game. Because that’s what it is.