Ever since I got the Exxon dongle (Speedpass) years ago, I have been filling my own tank. I actually get two cents cheaper than the cash price in some of my local gas stations by using the dongle. According to Exxon, it is up to the privately owned gas station which price to charge you when using the dongle, cash or credit.
In all these years, at least 15, the attendant approaches me and asks if I am OK. Once they receive an affirmative answer, they walk away. My local gas station knows me and just wave when I pull in and let me do my own.
That being said, I can not wait to get out of NJ. I see NC in my future.