I'm a backyard smoker, not a competitor or a caterer. I've watched a lot of videos about trimming briskets. Most appear WAY over-trimmed to me. I just trim off hard fat and discolored fat. I don't worry one bit about the quarter-inch thick recommendation or silver-skin. Silver-skin will render tender like all connective tissue.
I avoid trimming meat by selecting packers with an even cut and minimal tapering at the flat. I've never had a problem recognizing how to cut against the grain, so slicing off meat to show the grain direction is just a waste of money.
I've rendered trimmed fat on the stovetop. Can't say I cared for cooking with rendered beef fat. Much prefer bacon fat and rendered pork butt fat.
Leftovers get vac-sealed and frozen, or used in soups, chili, or Mexican dishes.