Grit for the tiny cost of an “in-line” filter and the costly repairs that come with injectors it is a cheap cautionary thing to do.
Regarding filtering from the pumps. From my experience, yes they do sell us dirt. The sooner you catch it the better.
I have filled at some stations where the flow is extremely slow. Why do you think that is? I’d suggest plugged filters drawing **** from the bulk tanks.
All my fuel goes into auxiliary tank.
I have seen dirt right in the fuel line fittings at the injectors on a Duramax.
You can’t be to careful when it comes to the need for clean fuel in today’s trucks.