I would round off the corners on the flat,they're thin and will be dry.

That grill grate looks like it’s never seen meat.

I start slicing on the lean part, perpendicular to the grain. When I get to the fatty part, I separate the two sections, then lay the fatty piece back on top of the lean with the grains lined up. Then continue slicing both at the same time, both against the grain.

This way when serving, it keeps lean and fatty pieces separated so that the uneducated people can take the lean meat, thus leaving the fatty pieces for those with more refined tastes.

I would have trimmed it, but I like a smooth trim. No pockets, flaps/overlays, big dips, pointy or thin edges, no pieces of loose fat, etc. Its all subjective though. If you don't trim certain parts and they don't burn or dry up, it doesn't really matter. The main things are not overtrimming, and getting your good fats to the right thickness.

Most times I trim to as close to a rectangle as I can get, but sometimes I will leave a chunk on the point that I know will be ready prior to the rest of the brisket being ready, and I will carve it off and eat it while standing at the smoker. Cook’s treat. My daughter has figured this trick out and hovers around the smoker waiting for me to cut it off the brisket.

Hindsight, but I should have trimmed it off. It dried up and wasn't any good.

I pulled it off at 10 hours, but I probably should have pulled it off at 8.5. I've struggled with briskets =(

If you're just gonna eat it around the house then that's fine. Optimally it should have been trimmed off, but then what do you do with that hunk of meat?
When you're trimming 40-60 a day it's a lot different. They all need to cook uniformly (or as close as possible), and we grind that meat up to be re-purposed.

Im more worried about the taste than the looks.

I will carve off any irregularities at the time I wrap the brisket.. cooks treats