I never pull up when done. I roll in and rarely wait as there is usually one open. I run in and leave a card, fuel, and go back in to sign and go. Since I am less then 100 gallons, it does not take long. You want to be outside listening for the fuel to come up into the filler tube on the big nozzles as the fuel will shoot 5 feet out and some will not auto stop right away. Stop it and top it off when it gets close manually. No mess, no waste.
I have seen truckers take a TON of time at the pumps. I would not worry about taking too much time.
I would be very cautious about letting anyone out during the stops. It is a very bustling area with trucks in and out and I certainly would not let my wife stroll into some truck stops. They can be unsavory at times. Know your surroundings.
I prefer the truck stops over a regular quickie mart gas station. And you can usually top the DEF off from the pump a lot cheaper than the boxed DEF.
WW