If you keep adding coats thinking it will fill in and level out, it won't. The pores are always going to be lower than the rest of the surface. You have to sand down the higher surface until it reaches the level of the pores.
I'm surprised at the suggestion of 220, the wet 800 chewed through with very light pressure almost all the way to the stain. Need more experience with all of this.
Thanks, I'll have to search the old GTA that is archived for this info.