wrap once you get the bark you want, not at a specific temp. Stop cooking brisket (or any meat for that matter) by temp and start using doing CPR (Yes, cardiopulmonary resuscitation).
The first thing you learn in CPR is "Look. Listen. Feel.". Look for the right indicators. Listen, not as important, lol. Feel the meat for doneness. Temps are meaningless and will only distract you.
2013 Stumps Classic - Delivered 4/15/13
Large BGE - Rescued 2012
2010 WSM 22.5"
2010 Weber genesis gas grill
Rescued 22.5 Weber One-touch gold
BBQ Guru CyberQ
2011 Built UDS - Retired