I agree that is isn't life or death to my tractor issue. I don't expect my tractor engine to explode if I use PS. However, I'm looking for a fuel additive that extends the shelf life of my fuel, mostly because my storage tank sits outside in the sun. Even though my tank is painted white it does get warm. I'm not looking to pay for an additive that actually shortens the shelf life. I'd rather use nothing.
I don't think they the PS people can give you a time frame like 6 months or a year without knowing the temperature that the fuel is stored at. If you can keep the fuel cool, using PS probably doesn't shorten the shelf life by a lot.