Why shouldn’t I use them between the fuel cell and fuel pump? All I see anymore is how there needs to be a filter pre and post pump.

I am currently using a Holley blue pump. I have never seen anything stating a micron rating for it. [/quote]
I was told by Magnafuel to use a 100 micron or bigger filter between the tank and there pumps, I used a BG 500 filter that had a paper element in it(10 micron rating ) and could not richen the mixture up enough to slow the car down, the wide ban showed it going lean from the starting line and got leaner as it accelerated, that was with their 275 pump
I bought a bigger 300 pump and had the exact same results on the wide ban so I change the filter to a bigger 80 micron rating and it went rich
On your deal you may be fine with those filters with the small Holley blue pump, it depends on how much power your going to make