I suspect you have taken off more fat than you need to @David Chang. I tended to have a bit of a fat cap left on the few briskets that I have cooked and that helped with the taste too. I just did a search for an Aaron Franklin brisket prep and he cleans the underside off well but leaves a fat cap on top. Is that the same for you or are both sides of your brisket clear of fat per your photos above?