If your in a MH and the fuel fill is right next to the fridge or hot water heater vents, I might consider it. But honestly, I can't recall every spraying gasoline outside the vehicle and modern systems largely capture the fumes anyway.
But since it's the sparks that are a concern, do you disconnect and shut down the 12v system before you pull into a gas station...of wait, you can drive with the 12v system shut off. Unless you've replaced your alternator and starter with a marine spark protection...there will be plenty of sparks if there are any fumes.
Of course, out in the open air, it might startle you a bit but is unlikely to do much more. Kind of like too much lighter fluid on the campfire. You get a big whoosh but not much else. Explosions require the fuel/oxygen mixture to be contained.