I ran the first small filter to nearly 400 hours before replacing it and it was still flowing fine at that point but I was going into winter and didn't want to be dealing with it in the winter.
I run all of my diesel through a screen before putting it in the tractor. I have a large fuel funnel with the brass screen and dump a fuel jug through the funnel and screen into the jug which I use with the battery shut off pump. The screen always catches debris, not a lot, but just enough that over time, it would clog the filter. The debris is fine, next time I run the fuel through the funnel and screen, I will take a picture of what it catches.
This process and treating all of the fuel year around helps minimize any problems and I believe its worth the effort. Here is the funnel I use.
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