Imo, you should smoke those big bones rubbed with SPOG at 285F, high enough to correctly melt the hard fat out anf inside the meat.
My cooking time at that T is minimum 5 hours for short plate beef ribs.
From that moment on, I check with any kind of probe you like (always the same to get practice with it) and when ready pull them off the smoker, let it vent a while and rest in double foil double blanckets for 1 hour.
Enjoy.