Trimming is important, not just the fat cap but also the deckel and the silverskin. There is a lot fat in the body of a brisket that will not render, you have to remove it pre-cook. Franklin has a very good Youtube video that helps visualize trimming. Also want to trim up the point and the flat to make sure you have a somewhat uniform piece of meat.
I prefer to smoke at 275 uncovered and wrap in butchers paper at around 175, pull at 195 and for me this is most improtant, it needs to rest in a cooler or cambro for at least 4 hours
PS- Smoke your trimming as well and use them in your baked beans
Franklins video