Finally done! The chuck roasts took 7 hours to hit 195 (not bad). Next time, for burnt ends, I'm pulling at 185, since they're finish cooking as cubes). 1 hour rest in foil before cubing.
Once the roasts cooled a bit (1 hour), they were cubed. As normal, a put them in a big bowl and coated with honey, my St Louis BBQ sauce, and rub (Memphis BBQ Company, this time). Then, back in the smoker at 240 for 1.5 hours (2 oz mesquite).
The results were great. While brisket point is ideal for burnt ends, the chuck is not a bad substitute!