Maybe this will help:
Brake Adjuster - How Drum Brakes Work | HowStuffWorks
It shows how a "normal" drum brake adjusts on a car. These usually adjusted when you backed up and stepped on the brake. If the brake pad has worn down, it moves farther, which allows the lever to turn the star wheel one notch. Then the pad doesn't move back to it's original position, but a little less. Now you don't have to push the brake pedal as far the next time you brake. The Nev-R-Adjusts seems to have it arranged so it adjusts when you brake going forward.
With the old car brakes, if I remember correctly, I think you were able to back off the star wheel even with the lever against it. (I've done a few times, but it's been a long time ago.) Apparently, per the e-trailer video, you need to push the lever out of the way on the Nev-R-Adjust's if you want to back off on the star wheel.
1988 Coleman Sequoia - popup (1987-2007)
2012 Roo19 - hybid (2012-2015)
2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10