Yes, I also noted that the linked company made\sold additives but also that their estimated cost of "blended" fuel was low based on my costs.
At least some of the local retail stations use a combination like this one in the picture below that I took a while back. The former Holiday Station (now Circle K) used to post signage as to what the treated fuel flow temp was for during the various months of the cold season based on regional average lows. They also used a blend plus additives.
I think the bulk use of additives has become much more common as it's easier to adjust for regionally and as the season changes.
https://photos.app.goo.gl/J3JLGqqzz8tJQVkCA
I'm continuing to have frustrations with posting pictures here...