So I gave up on all the rice & legumes stuff, and went for a 15 pound pork shoulder instead :
Slathered in jerk paste, slashed & stabbed with a big knife, jerk paste pushed into the cuts (that's gotta sting), then a few hours at 275F to get warm before leaving it overnight at 250F. Total cook time about 12 hours to reach 195F internal - less time than usual, but the pork shoulder was one of the thinner ones in the store.
Surprisingly good considering that the closest it came to the smoker was while I was bringing groceries from the car into the house.