Please excuse my lower 48 ignorance; but living in Alaska for 36 plus years. As a rule we switch from #2 diesel for summer to #1 diesel for winter, long before their is any chance of gelling. This occurs at the distribution level so everything is switched over (home heating fuel, everything at the pump, etc.).
Gelling is really not an issue nor a concern, even at our temperature extremes (-60 or more). Guessing the lower 48 does not do the same?
I've never run any fancy additives, nor anti-gelling agents. It all sounds a little like the snake oil salesman. In My Experience, FWIW
I have / will throw a quart of ATF in the tank about once a year for non-intrusive injector maintenance.
P.S.
Changed my fuel filter once, because I bought the truck used with about 100K on it. Now has about 180K on it. And has consumed about 11,500 (counter resets at 10K) Gallons of diesel since new. If I had to change the fuel filter every 15K, I'd be finding a cleaner supplier to purchase from, because whatever diesel your buying has way more particulate / water in it than it should have. 15K is ridicules. IMO