I'm not an SRG driver but I've cooked a lot of briskets in a lot of different cookers over the years and have finally become fairly comfortable with this unpredictable chunk. Here are some suggestions based on general brisket tendencies and characteristics:
1. Don't over-trim it. Fat equals flavor, at least in reasonable amounts. Leave about 1/4" on the fat side and cook fat side down because this fat works as a moisture barrier during the cook. Do not separate the point and flat until cooking is finished because the point will help baste the flat. If you cook a flat by itself you'll have moisture problems.
2. Inject with very lightly seasoned broth, deep and shallow, more injections in the flat than in the point. Injections are moisture insurance
3. If you can get your SRG to produce some smoke, use it to infuse smokiness first. See if you can get at least 30 minutes to an hour of decent blue smoke, not heavy white smoke (causes creosote or "charcoal lighter" flavor in meat). If the SRG won't go "low and slow" (250 degrees or less) use your oven instead (after the smoke).
4. When the IT reaches about 150 or so, wrap the brisket in a double layer of heavy foil. It will then start to produce its own delicious basting juice inside the foil and will "braise" somewhat insuring tenderness.
5. If you us a rub, avoid sugar-based ones. Beef flavor is enhanced by spicing and salt, not sugar.
6. When the IT reaches 195 pull the meat, cease the cook and let it rest for at least thirty minutes. If you need longer, put it in an empty cooler covered with towels and it will stay hot for hours (this is called the FTC method).
7. Separate the flat and point last. Trim off the rest of any fat you don't want to eat. Slice the flat ACROSS the grain, never with the grain.
8. A good use for the point is to dice it into 1" cubes, coat them with a sweet barbecue sauce and make "burnt ends" for snacks and sandwiches. Alternatively you can slice it for service, too but the texture isn't as good as the flat this way.
Have fun and enjoy your work. Maybe you'll perfect a SRG brisket
Hub