Michael if you can find my toot on epoxy pore filling in the toot section I make a big deal out of how epoxy should not be "painted" on but instead "mashed" into the pores with downward pressure from someone else's credit card....
One pro finsher that I know uses foam brushes and that works well for him.
The confusion when using cards is the word "squeegee" (not sure if I spelled that right and my shop computer does not spell check...). So one tends to believe that the card is to remove the excess which is can and is used for too. But it's also used with proper technique to mash the epoxy into the pores.
Coat one generally is to completely wet the pore bottoms so that coat two will stick in the pores. Coat two does the heavy lifting so-to-speak and often it's the case that this is all I need to do, two coats. I've been thickening coat two wiht microballons and that helps too.