As long as you keep it covered in liquid and the fat and liquid doesn't boil away, you should be ok. I leave the fat cap on the top and take it off when cooking is over. Take the brisket out of the liquid and tent it with foil for 15 - 20 minutes before slicing (across the grain, of course). Use the remaining liquid to cook your cabbage. Low boil for 20 minutes.
Yea, there is plenty of liquid. Tried a little piece of carrot and potato, wow that has some bite, makes it come alive! It was only about 1/2 of a jalapena. I put it on at 9 AM and I’m going to eat it at 7 PM