I'm guessing you mean Fahrenheit as the measurement of temperature. Brisket is a challenge to get right. The flat is the leanest part of the brisket which makes it difficult to achieve a moist slice.
The bark will not be as crisp, but if you wrap at the correct time you will get a pretty good bark. This is generally around when the temperature of the brisket get around 160°F. To check when to wrap, scrap the surface of the meat with your fingernail, if the bark remains on the meat it is ready to wrap. If it comes away from the meat, continue to cook until it sticks to the meat. When ready to wrap, wrap it tight, and try to prevent air pockets that can trap steam.
Another method; some members will lay bacon on a rack, and place that above the rack that contains the brisket. The fat from the bacon drips on the brisket below, and baste it as it cooks. I've never tried this, since it will alter the taste of the brisket.
You can try brining with a simple salt and sugar brine. I have a brine mix that I use when I'm making burnt ends; 1 gallon water, 1 cup table salt, 1/2 white sugar. Submerge brisket in brine, refrigerate and brine for 2 hours. Do not go over 2 hours. You may want to reduce the salt in your rub.
You can also make an injection and inject your brisket. For a 3 lb. brisket you would only need about 5 ounces of injection. You can purchase beef marinade mix, and mix up as small or large of a batch you want. I know Blue Hog Beef Marinade is one that you can purchase. I don't use them because they have phosphates, and phosphates produce a metallic aftertaste in my mouth. Or use something like Zatarain's Cajun Injectors, but again it will alter the taste of the brisket.
FTC is an acronym used on this forum; Foil-Towel-Cooler. You wrap the brisket in foil (if not already wrapped]. Then wrap it in a towel. The towel serves two purposes. One, it acts as an extra layer of insulation. Two, it protects the plastic inside the cooler from the direct contact of the hot meat. Once wrap in a towel, place it in a dry cooler, and let it rest or to hold until you need it. With a small brisket flat, you could probably substitute the microwave in place of the cooler. You can add a little liquid, such as low sodium beef broth, apple juice or other liquid to the brisket before you FTC. While it is resting the brisket will absorb some of that liquid.