So, chef is correct, it will dry out the flat trying to get the point to temp. Something I do is separate them and smoke them together (stack them like they were never separated) until I start seeing a big temp difference, or I have the flat where I want it. Looking at bark and temp (170 to 180 for most of my smokes).
At this point you can wrap or move the flat to a cooler part of the smoker. Wrapping will make it cook faster, but let you focus on burnt ends.
Point meat around here is what the ends are made from.
Get the flat probe tender and pull it 198 to 210 for a brisket. Let it rest at least an hour to reintroduce the juices.
Forgot to say, I do spritz every 45 minutes to an hour on a brisket after 2 to 3 hours.
If this is your first one, my average brisket is around 16 hours. 15 to 18 lbs. untrimmed