Bludawg, if I had any doubts that the probe test is the way to go and ignore temp altogether, this finished them off! After all the reading of people pulling them between 190 and 203, I admit to freaking out at 209 not realizing what some posters said earlier about the hot and fast method having higher finishing temps because of the time needed to render. I'm convinced next brisket cook I'm using a small skewer and nothing connected to a readout!
As for the temp, I trust the thermometer. The 350F was in a convection oven, so it was potentially a bit hotter, and after fat trimming keep in mind the brisket was probably closer to 10 lbs. So I do think the center of the flat was 209F. All that said, clearly the right thing to do was to keep going!!
UF Aero, Weber 22.5" Performer Gold w/ Smokenator