Regarding the burnt ends. When should I remove the point from the flat? Should I let the entire brisket rest before separating the two or should I remove the point to make the burnt ends while the flat rests?
I like to separate the point/flat when the internal temp in the point is between the upper 150's to mid 160* range (the flat may be in the 180*+ range, as it cooks faster, typically)...this temp seems best for our liking of texture in the BE's. It will still have pink juices when sliced for cubing, and when cubed for the second smoke, the texture of the burnt ends seems best. A nice popping, but tender chew inside, and if done the way I like them, they get a crispy, crunchy exterior...it's an explosion of texture variations. If I separate at much over 170*, the burnt ends can get a bit drier interior, unless cut into larger pieces. I normally cube to about 1-1/4", but have gone to 1-1/2 to 1-3/4",depending on the temp I separated at (larger if higher temp).
When I separate, I decide what I'll do with the flat next for slicing, based on it's internal temp. If over 180*, I probe for tenderness, and if I feel little resistance, I foil to wrap in towels and rest. If it's not quite tender enough (some briskets will be, some will not), I may foil (or just re-season the freshly bared meat real quick), and return to the smoker to bring it up to 190* or so, then towel wrap to rest. While doing the final prep for the flat, I'm giving the point a few minutes to rest on the board before cubing for BE's. I smoke BE's at 225* for the bulk of 2-3 hours, depending on cube size, and like to bump to 275* or so to get the finished crispy texture, if needed.
If a bark is what you're after with the flat, don't foil to bring to finish temps, or the bark will soften a lot. It softens some when foiled to rest, but not as much. As soon as you foil, you begin a steaming process and with or without added liquids in the foil, the meat will give off a lot of water vapor. But most just like a tender slice for the flat, so foil away if that's your game.
If you haven't read a lot on BE's just yet, in my signature line there are several brisket smokes, most with BE's and methods I have used...each one a bit different than the other.
Eric