Advice on pumping DEF needed.

I buy my DEF at the local Ford dealer in 2 1/2 gallon jugs. So far in 18K miles, many of which were towing a 7200 lb trailer I've purchased 4 jugs and still have 2/3's of the last one sitting in the garage. One of these days maybe I'll be at some truck stop when the warning flashes "Less than 1/2 Full" and I'll buy some at the pump or maybe not cause I fill the DEF before I leave on a trip and I've only seen that warning once. The one time it got low enough to show the warning was the first tank and I purposely allowed it to get that low so I could see how long it took. After the first time I no longer believed all the drama on the web about trucks shutting down unexpectedly because it used so much DEF.

I guess some folks just got to make a mountain out of a molehill to be happy.